New Visualization Of Waves In Saturn’s Rings Puts You In The Keeler Gap

Universe Today - 19 August, 2016 - 20:29

Fans of astronomy are no doubt familiar with the work of Kevin Gill. In the past, he has brought us visualizations of what the Earth would look like if it had a system of rings, what a "Living Mars" would look like - i.e. if it was covered in oceans and lush vegetation - and an artistic rendition of the places we've been in our Solar System. In his latest work, which once again merges the artistic and astronomical, Gill has created a series of images that show Saturn's moon of Daphnis, and the effect it has on Saturn's Keeler Gap. Through these images - titled "Daphnis in the Keeler Gap" and "Daphnis and Waves Along the Keeler Gap" - we get to see an artistic rendition of how one of Saturn's moons interacts with its beautiful ring system. As one of Saturn's smallest moons - measuring just 8 km (~5 mi) in diameter - the existence of Daphnis had been previously inferred by astronomers based on the gravitational ripples that were observed on the outer edge of the Keeler Gap. This 42 km (26 mi) wide gap, which lies in Saturn's A Ring and is approximately 250 km from the its outer edge, is kept clear by Daphnis' orbit around the planet. In 2005, the Cassini space probe finally confirmed the existence of this tiny moon. After analyzing images provided by the probe, the Cassini Imaging Science Team concluded that Daphnis' path and orbit induce a wavy pattern in the edge of the gap. These waves reach a distance of 1.5 km (0.93 mi) above the ring, due to Daphnis being slightly inclined to the ring's plane. However, all the images taken by Cassini showed this effect from a great distance. In order to help people appreciate what it must look like close-up, Gill decided to create the visuals you see here. From his images, the passage of Daphnis is shown to give the A Ring a rippled, wavy appearance. In addition, one can see how Daphnis is inclined slightly above the plane of the A Ring, causing the waves to reach upward. As Kevin Gill told Universe Today via email, these images were the largely inspired by the most recent images of Saturn's rings that were provided by Cassini space probe, which returned to an equatorial orbit a few months ago after spending two years in high-inclination orbits: "These are inspired by a general interest in the moon-ring interactions and some recent Cassini views of Daphnis on the 15th (shown below). This is one of the many aspects of the Saturn system that I imagine would be absolutely breathtaking if you could see it in person and ended up being rather simple to model in Maya." [caption id="attachment_130366" align="aligncenter" width="580"]

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Categories: space

Europa Clipper Team Braces For Bad News

Universe Today - 19 August, 2016 - 19:58

Jupiter's moon Europa is a juicy target for exploration. Beneath its surface of ice there's a warm salty, ocean. Or potentially, at least. And if Earth is our guide, wherever you find a warm, salty, ocean, you find life. But finding it requires a dedicated, and unique, mission. If each of the bodies in our Solar System weren't so different from each other, we could just have one or two types of missions. Things would be much easier, but also much more boring. But Europa isn't boring, and it won't be easy to explore. Exploring it will require a complex, custom mission. That means expensive. NASA's proposed mission to Europa is called the Europa Clipper. It's been in the works for a few years now. But as the mission takes shape, and as the science gets worked out, a parallel process of budget wrangling is also ongoing. And as reported by there could be bad news incoming for the first-ever mission to Europa. At issue is next year's funding for the Europa Clipper. Officials with NASA’s Outer Planets Assessment Group are looking for ways to economize and cut costs for Fiscal Year (FY) 2017, while still staying on track for a mission launch in 2022. According to Bob Pappalardo, Europa Clipper's project scientist at the Jet Propulsion Laboratory, funding will be squeezed in 2017. “There is this squeeze in FY17 that we have,” said Pappalardo. “We’re asking the instrument teams and various other aspects of the project, given that squeeze, what will it take in the out years to maintain that ’22 launch." As for the actual dollar amounts, there are different numbers floating around, and they don't all jive with each other. In 2016, the Europa Mission received $175 million from Congress, but in the administration's budget proposal for 2017, they only requested $49.6 million. There's clearly some uncertainty in these numbers, and that uncertainty is reflected in Congress, too. An FY 2017 House bill earmarks $260 million for the Europa mission. And the Senate has crafted a bill in support of the mission, but doesn't allocate any funding for it. Neither the Senate nor the Congress has passed their bills. This is not the first time that a mis-alignment has appeared between NASA and the different levels of government when it comes to funding. It's pretty common. It's also pretty common for the higher level of funding to prevail. But it's odd that NASA's requested amount is so low. NASA's own low figure of $49.6 million is fuelling the perception that they themselves are losing interest in the Europa Clipper. But is reporting that that is not the case. According to Curt Niebur, NASA's program scientist for the Europa mission, “Everyone is aware of how supportive and generous Congress has been of this mission, and I’m happy to say that that support and encouragement is now shared by the administration, and by NASA as well. Everybody is on board the Europa Clipper and getting this mission to the launch pad as soon as our technical challenges and our budget will allow.” [embed][/embed] What all this seems to mean is that the initial science and instrumentation for the mission will be maintained, but no additional capacity will be added. NASA is no longer considering things like free-flying probes to measure the plumes of water ice coming off the moon. According to Niebur, “The additional science value provided by these additions was not commensurate with the associated impact to resources, to accommodation, to cost. There just wasn’t enough science there to balance that out.” The Europa Clipper will be a direct shot to Europa, without any gravity assist on the way. It will likely be powered by the Space Launch System. The main goal of the mission is to learn more about the icy moon's potential habitability. There are tantalizing clues that it has an ocean about 100 km thick, kept warm by the gravity-tidal interactions with Jupiter, and possibly by radioactive decay in the rocky mantle. There's also some evidence that the composition of the sub-surface ocean is similar to Earth's. Mars is a fascinating target, no doubt about it. But as far as harbouring life, Europa might be a better bet. Europa's warm, salty ocean versus Mar's dry, cold surface? A lot of resources have been spent studying Mars, and the Europa mission represents a shift in resources in that regard. It's unfortunate that a few tens of million dollars here or there can hamper our search for life beyond Earth. But the USA is a democracy, so that's the way it is. These discrepancies and possible disputes between NASA and the different levels of government may seem disconcerting, but that's the way these things get done. At least we hope it is. Sources: Europa on Universe Today:

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Categories: space

Venus-like Exoplanet 39 Light Years Distant Is Probably Baked & Sterile

Universe Today - 19 August, 2016 - 18:47

Last year, astronomers discovered a terrestrial exoplanet orbiting GJ 1132, a red dwarf star located just 12 parsecs (39 light years) away from Earth. Though too close to its parent star to be anything other than extremely hot, astronomers were intrigued to note that it appeared to still be cool enough to have an atmosphere. This was quite exciting, as it represented numerous opportunities for research. In essence, the planet appeared to be "Venus-like" - i.e. very hot, but still in possession of an atmosphere. What's more, it was close enough to our Solar System that its atmosphere could be studied in detail. However, a debate began over whether its atmosphere would be hot and wet, or thin and tenuous. And after a year of study, a team of astronomers from the CfA believe they have unlocked that mystery.

In addition to being relatively close to our own Solar System in astronomical terms, the Venus-like exoplanet GJ 1132b also has a relatively small orbital period around its star. This means that opportunities to spot it as it passes in front of its star (i.e. the Transit Method), occur quite often.

This makes it an excellent target for detailed observation and study, which in turn will help astronomers to learn more about terrestrial exoplanets that orbit close to red dwarf stars. But as noted already, astronomers were divided on the issue of GJ 1132b's atmosphere. Thanks to the research efforts of Laura Schaefer and her colleagues from the Harvard-Smithsonian Center for Astrophysics (CfA), it now appears that the case for a thin atmosphere is the far more likely. Interestingly enough, this was confirmed by determining just how much oxygen the planet has in its atmosphere. For the sake of their study, which was outlined in a paper that approved for publication in The Astrophysical Journal - titled "Predictions of the atmospheric composition of GJ 1132b" - they explain how they used a "magma ocean-atmosphere" model to determine what would happen to GJ 1132b over time if it began with a water-rich atmosphere. They began with the knowledge that a planet like GJ 1132b - which orbits its star at a distance of 2.25 million km (1.4 million mi) - would be subjected to intense amounts of ultraviolet light. This would result in any water vapor in the atmosphere being broken down into hydrogen and oxygen (a process known as photolysis), with the hydrogen escaping into space and the oxygen being retained. At the same time, they determined that the planet's atmosphere and proximity to its star would lead to a severe greenhouse effect that would leave the surface molten for a long time. This "magma ocean" would likely interact with the atmosphere by absorbing some of the oxygen. How much would be absorbed and how much would be retained was the big question. They concluded that the planet's magma ocean would absorb about one-tenth of the oxygen in the atmosphere. The majority of the remaining 90 percent, according to their model, would be lost to space while a small margin would linger around the planet. This proved to be very much consistent with measurements made of the planet thus far. As Dr. Laura Schaefer explained to Universe Today via email: "We determined that the planet would likely have a thin atmosphere by doing a suite of models looking at atmospheric loss and interaction with a surface magma ocean. For the allowable composition range (esp. the abundance of water) based on the current mass measurement, nearly all of the allowed compositions resulted in thin atmospheres, except at the very extreme upper end of the range." This magma ocean-atmosphere model could not only help scientists to study terrestrial exoplanets that orbit close to their parent stars, but also to understand how our own planet Venus came to be. For some time, scientists have theorized that Venus began with significant amounts of water on its surface, but that it then underwent a significant change. This ocean is believed to have evaporated due to Venus' closer proximity to the Sun, with the ensuing water vapor triggering a runaway greenhouse effect. Over time, ultraviolet radiation from the Sun broke apart the water molecules, resulting in the hot, virtually waterless atmosphere we see today. However, what happened to all the oxygen has remained a mystery. "We also have plans to use this model in the future to study Venus, which may have once had about the same amount of water as the Earth but is now very dry," said Schaefer. "There is very little O2 left in Venus' atmosphere, so this model would help us understand what happened to that oxygen (whether it was lost to space or absorbed by the planet's mantle)." Schaefer predicts that their model will also assist researchers with the study of other, similar exoplanets. One example is the TRAPPIST-1 system, which contains three planets that may lie with the star's the habitable zone. But as Schaefer put it, the real value lies in the fact that we are more likely to find "Venus-like" worlds down the road: "Most of the rocky planets that we know of and will discover in the near future will likely be hotter than the Earth or even Venus, just because it is easier to detect hotter planets. So there are a lot of planets out there similar to GJ 1132b just waiting to be studied!" Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. It's scientists are dedicated to studying the origin, evolution and future of the universe. And be sure to check out this video, courtesy of MIT news: Further Reading: CfA, arXiv

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Categories: space

Cooking Up Life in the Cosmic Kitchen

Universe Today - 18 August, 2016 - 16:29

Kitchens are where we create. From crumb cake to corn on the cob, it happens here. If you're like me, you've occasionally left a turkey too long in the oven or charred the grilled chicken. When meat gets burned, among the smells informing your nose of the bad news are flat molecules consisting of carbon atoms arranged in a honeycomb pattern called PAHs or polycyclic aromatic hydrocarbons. PAHs make up about 10% of the carbon in the universe and are not only found in your kitchen but also in outer space, where they were discovered in 1998. Even comets and meteorites contain PAHs. From the illustration, you can see they're made up of several to many interconnected rings of carbon atoms arranged in different ways to make different compounds. The more rings, the more complex the molecule, but the underlying pattern is the same for all. All life on Earth is based on carbon. A quick look at the human body reveals that 18.5% of it is made of that element alone. Why is carbon so crucial? Because it's able to bond to itself and a host of other atoms in a variety of ways to create a lots of complex molecules that allow living organisms to perform many functions. Carbon-rich PAHs may even have been involved in the evolution of life since they come in many forms with potentially many functions. One of those may have been to encourage the formation of RNA (partner to the "life molecule" DNA). In the continuing quest to learn how simple carbon molecules evolve into more complex ones and what role those compounds might play in the origin of life, an international team of researchers have focused NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) and other observatories on PAHs found within the colorful Iris Nebula in the northern constellation Cepheus the King. Bavo Croiset of Leiden University in the Netherlands and team determined that when PAHs in the nebula are hit by ultraviolet radiation from its central star, they evolve into larger, more complex molecules. Scientists hypothesize that the growth of complex organic molecules like PAHs is one of the steps leading to the emergence of life. Strong UV light from a newborn massive star like the one that sets the Iris Nebula aglow would tend to break down large organic molecules into smaller ones, rather than build them up, according to the current view. To test this idea, researchers wanted to estimate the size of the molecules at various locations relative to the central star. Croiset’s team used SOFIA to get above most of the water vapor in the atmosphere so he could observe the nebula in infrared light, a form of light invisible to our eyes that we detect as heat. SOFIA’s instruments are sensitive to two infrared wavelengths that are produced by these particular molecules, which can be used to estimate their size. The team analyzed the SOFIA images in combination with data previously obtained by the Spitzer infrared space observatory, the Hubble Space Telescope and the Canada-France-Hawaii Telescope on the Big Island of Hawaii. The analysis indicates that the size of the PAH molecules in this nebula vary by location in a clear pattern. The average size of the molecules in the nebula’s central cavity surrounding the young star is larger than on the surface of the cloud at the outer edge of the cavity. They also got a surprise: radiation from the star resulted in net growth in the number of complex PAHs rather than their destruction into smaller pieces. In a paper published in Astronomy and Astrophysics, the team concluded that this molecular size variation is due both to some of the smallest molecules being destroyed by the harsh ultraviolet radiation field of the star, and to medium-sized molecules being irradiated so they combine into larger molecules. So much starts with stars. Not only do they create the carbon atoms at the foundation of biology, but it would appear they shepherd them into more complex forms, too. Truly, we can thank our lucky stars!

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Categories: space

What are the Planets of the Solar System?

Universe Today - 17 August, 2016 - 23:15

At one time, humans believed that the Earth was the center of the Universe; that the Sun, Moon, planets and stars all revolved around us. It was only after centuries of ongoing observations and improved instrumentation that astronomers came to understand that we are in fact part a larger system of planets that revolve around the Sun. And it has only been within the last century that we've come to understand just how big our Solar System is. And even now, we are still learning. In the past few decades, the total number of celestial bodies and moons that are known to orbit the Sun has expanded. We have also come to debate the definition of "planet" (a controversial topic indeed!) and introduced additional classifications - like dwarf planet, minor planet, plutoid, etc. - to account for new finds. So just how many planets are there and what is special about them? Let's run through them one by one, shall we? Mercury: As you travel outward from the Sun, Mercury is the closest planet. It orbits the Sun at an average distance of 58 million km (36 million mi). Mercury is airless, and so without any significant atmosphere to hold in the heat, it has dramatic temperature differences. The side that faces the Sun experiences temperatures as high as 420 °C (788 °F), and then the side in shadow goes down to -173 °C (-279.4 °F). Like Venus, Earth and Mars, Mercury is a terrestrial planet, which means it is composed largely of refractory minerals such as the silicates and metals such as iron and nickel. These elements are also differentiated between a metallic core and a silicate mantle and crust, with Mercury possessing a larger-than-average core. Multiple theories have been proposed to explain this, the most widely accepted being that the impact from a planetesimal in the past blew off much of its mantle material. Mercury is the smallest planet in the Solar System, measuring just 4879 km across at its equator. However, it is second densest planet in the Solar System, with a density of 5.427 g/cm3 - which is the second only to Earth. Because of this, Mercury experiences a gravitational pull that is roughly 38% that of Earth's (0.38 g). Mercury also has the most eccentric orbit of any planet in the Solar System (0.205), which means its distance from the Sun ranges from 46 to 70 million km (29-43 million mi). The planet also takes 87.969 Earth days to complete an orbit. But with an average orbital speed of 47.362 km/s, Mercury also takes 58.646 days to complete a single rotation. Combined with its eccentric orbit, this means that it takes 176 Earth days for the Sun to return to the same place in the sky (i.e. a solar day) on Mercury, which is twice as long as a single Hermian year. Mercury also has the lowest axial tilt of any planet in the Solar System – approximately 0.027 degrees - compared to Jupiter’s 3.1 degrees, which is the second smallest. Mercury has only been visited two times by spacecraft, the first being the Mariner 10 probe, which conducted a flyby of the planet back in the mid-1970s. It wasn't until 2008 that another spacecraft from Earth made a close flyby of Mercury (the MESSENGER probe) which took new images of its surface, shed light on its geological history, and confirmed the presence of water ice and organic molecules in its northern polar region. In summary, Mercury is made special by the fact it is small, eccentric, and varies between extremes of hot and cold. It's also very mineral rich, and quite dense! Venus: Venus is the second planet in the Solar System, and is Earth's virtual twin in terms of size and mass. With a mass of 4.8676×1024 kg and a mean radius of about 6,052 km, it is approximately 81.5% as massive as Earth and 95% as large. Like Earth (and Mercury and Mars), it is a terrestrial planet, composed of rocks and minerals that are differentiated. But apart from these similarities, Venus is very different from Earth. Its atmosphere is composed primarily of carbon dioxide (96%), along with nitrogen and a few other gases. This dense cloud cloaks the planet, making surface observation very difficult, and helps heat it up to 460 °C (860 °F). The atmospheric pressure is also 92 times that of Earth's atmosphere, and poisonous clouds of carbon dioxide and sulfuric acid rain are commonplace. Venus orbits the Sun at an average distance of about 0.72 AU (108 million km; 67 million mi) with almost no eccentricity. In fact, with its farthest orbit (aphelion) of 0.728 AU (108,939,000 km) and closest orbit (perihelion) of 0.718 AU (107,477,000 km), it has the most circular orbit of any planet in the Solar System. The planet completes an orbit around the Sun every 224.65 days, meaning that a year on Venus is 61.5% as long as a year on Earth. When Venus lies between Earth and the Sun, a position known as inferior conjunction, it makes the closest approach to Earth of any planet, at an average distance of 41 million km. This takes place, on average, once every 584 days, and is the reason why Venus is the closest planet to Earth. The planet completes an orbit around the Sun every 224.65 days, meaning that a year on Venus is 61.5% as long as a year on Earth. Unlike most other planets in the Solar System, which rotate on their axes in an counter-clockwise direction, Venus rotates clockwise (called “retrograde” rotation). It also rotates very slowly, taking 243 Earth days to complete a single rotation. This is not only the slowest rotation period of any planet, it also means that a single day on Venus lasts longer than a Venusian year. Venus' atmosphere is also known to experience lightning storms. Since Venus does not experience rainfall (except in the form of sulfuric acid), it has been theorized that the lightning is being caused by volcanic eruptions. Several spacecraft have visited Venus, and a few landers have even made it to the surface to send back images of its hellish landscape. Even though there were made of metal, these landers only survived a few hours at best. Venus is made special by the fact that it is very much like Earth, but also radically different. It's thick atmosphere could crush a living being, its heat could melt lead, and its acid rain could dissolve flesh, bone and metal alike! It also rotates very slowly, and backwards relative to the other plants. Earth: Earth is our home, and the third planet from the Sun. With a mean radius of 6371 km and a mass of 5.97×1024 kg, it is the fifth largest and fifth most-massive planet in the Solar System. And with a mean density of 5.514 g/cm³, it is the densest planet in the Solar System. Like Mercury, Venus and Mars, Earth is a terrestrial planet. But unlike these other planets, Earth's core is differentiated between a solid inner core and liquid outer core. The outer core also spins in the opposite direction as the planet, which is believed to create a dynamo effect that gives Earth its protective magnetosphere. Combined with a atmosphere that is neither too thin nor too thick, Earth is the only planet in the Solar System known to support life. In terms of its orbit, Earth has a very minor eccentricity (approx. 0.0167) and ranges in its distance from the Sun between 147,095,000 km (0.983 AU) at perihelion to 151,930,000 km (1.015 AU) at aphelion. This works out to an average distance (aka. semi-major axis) of 149,598,261 km, which is the basis of a single Astronomical Unit (AU) The Earth has an orbital period of 365.25 days, which is the equivalent of 1.000017 Julian years. This means that every four years (in what is known as a Leap Year), the Earth calendar must include an extra day. Though a single solar day on Earth is considered to be 24 hours long, our planet takes precisely 23h 56m and 4 s to complete a single sidereal rotation (0.997 Earth days). Earth’s axis is also tilted 23.439281° away from the perpendicular of its orbital plane, which is responsible for producing seasonal variations on the planet’s surface with a period of one tropical year (365.24 solar days). In addition to producing variations in terms of temperature, this also results in variations in the amount of sunlight a hemisphere receives during the course of a year. Earth has only a single moon: the Moon. Thanks to examinations of Moon rocks that were brought back to Earth by the Apollo missions, the predominant theory states that the Moon was created roughly 4.5 billion years ago from a collision between Earth and a Mars-sized object (known as Theia). This collision created a massive cloud of debris that began circling our planet, which eventually coalesced to form the Moon we see today. What makes Earth special, you know, aside from the fact that it is our home and where we originated? It is the only planet in the Solar System where liquid, flowing water exists in abundance on its surface, has a viable atmosphere, and a protective magnetosphere. In other words, it is the only planet (or Solar body) that we know of where life can exist on the surface. In addition, no planet in the Solar System has been studied as well as Earth, whether it be from the surface or from space. Thousands of spacecraft have been launched to study the planet, measuring its atmosphere, land masses, vegetation, water, and human impact. Our understanding of what makes our planet unique in our Solar System has helped in the search for Earth-like planets in other systems. Mars: The fourth planet from the Sun is Mars, which is also the second smallest planet in the Solar System. It has a radius of approximately 3,396 km at its equator, and 3,376 km at its polar regions – which is the equivalent of roughly 0.53 Earths. While it is roughly half the size of Earth, it’s mass – 6.4185 x 10²³ kg – is only 0.151 that of Earth’s. It's density is also lower than Earths, which leads to it experiencing about 1/3rd Earth's gravity (0.376 g). It’s axial tilt is very similar to Earth’s, being inclined 25.19° to its orbital plane (Earth’s axial tilt is just over 23°), which means Mars also experiences seasons. Mars has almost no atmosphere to help trap heat from the Sun, and so temperatures can plunge to a low of -140 °C (-220 °F) in the Martian winter. However, at the height of summer, temperatures can get up to 20 °C (68 °F) during midday at the equator. However, recent data obtained by the Curiosity rover and numerous orbiters have concluded that Mars once had a denser atmosphere. Its loss, according to data obtained by NASA's Mars Atmosphere and Volatile Evolution (MAVEN), the atmosphere was stripped away by solar wind over the course of a 500 million year period, beginning 4.2 billion years ago. At its greatest distance from the Sun (aphelion), Mars orbits at a distance of 1.666 AUs, or 249.2 million km. At perihelion, when it is closest to the Sun, it orbits at a distance of 1.3814 AUs, or 206.7 million km. At this distance, Mars takes 686.971 Earth days, the equivalent of 1.88 Earth years, to complete a rotation of the Sun. In Martian days (aka. Sols, which are equal to one day and 40 Earth minutes), a Martian year is 668.5991 Sols. Like Mercury, Venus, and Earth, Mars is a terrestrial planet, composed mainly of silicate rock and metals that are differentiated between a core, mantle and crust. The red-orange appearance of the Martian surface is caused by iron oxide, more commonly known as hematite (or rust). The presence of other minerals in the surface dust allow for other common surface colors, including golden, brown, tan, green, and others. Although liquid water cannot exist on Mars’ surface, owing to its thin atmosphere, large concentrations of ice water exist within the polar ice caps – Planum Boreum and Planum Australe. In addition, a permafrost mantle stretches from the pole to latitudes of about 60°, meaning that water exists beneath much of the Martian surface in the form of ice water. Radar data and soil samples have confirmed the presence of shallow subsurface water at the middle latitudes as well. Mars has two tiny asteroid-sized moons: Phobos and Deimos. Because of their size and shape, the predominant theory is that Mars acquired these two moons after they were kicked out of the Asteroid Belt by Jupiter's gravity. Mars has been heavily studied by spacecraft. There are multiple rovers and landers currently on the surface and a small fleet orbiters flying overhead. Recent missions include the Curiosity Rover, which gathered ample evidence on Mars' water past, and the groundbreaking discovery of finding  organic molecules on the surface. Upcoming missions include NASA's InSight lander and the Exomars rover. Hence, Mars' special nature lies in the fact that it also terrestrial and lies within the outer edge of the Sun's habitable zone. And whereas it is a cold, dry place today, it once had an thicker atmosphere and plentiful water on its surface. Jupiter: Mighty Jupiter is the fouth planet for our Sun and the biggest planet in our Solar System. Jupiter’s mass, volume, surface area and mean circumference are 1.8981 x 1027 kg, 1.43128 x 1015 km3, 6.1419 x 1010 km2, and 4.39264 x 105 km respectively. To put that in perspective, Jupiter diameter is roughly 11 times that of Earth, and 2.5 the mass of all the other planets in the Solar System combined. But, being a gas giant, it has a relatively low density – 1.326 g/cm3 – which is less than one quarter of Earth’s. This means that while Jupiter’s volume is equivalent to about 1,321 Earths, it is only 318 times as massive. The low density is one way scientists are able to determine that it is made mostly of gases, though the debate still rages on what exists at its core (see below).

Jupiter orbits the Sun at an average distance (semi-major axis) of 778,299,000 km (5.2 AU), ranging from 740,550,000 km (4.95 AU) at perihelion and 816,040,000 km (5.455 AU) at aphelion. At this distance, Jupiter takes 11.8618 Earth years to complete a single orbit of the Sun. In other words, a single Jovian year lasts the equivalent of 4,332.59 Earth days.

However, Jupiter’s rotation is the fastest of all the Solar System’s planets, completing a rotation on its axis in slightly less than ten hours (9 hours, 55 minutes and 30 seconds to be exact). Therefore, a single Jovian year lasts 10,475.8 Jovian solar days. This orbital period is two-fifths that of Saturn, which means that the two largest planets in our Solar System form a 5:2 orbital resonance. Much like Earth, Jupiter experiences auroras near its northern and southern poles. But on Jupiter, the auroral activity is much more intense and rarely ever stops. The intense radiation, Jupiter’s magnetic field, and the abundance of material from Io’s volcanoes that react with Jupiter’s ionosphere create a light show that is truly spectacular. Jupiter also experiences violent weather patterns. Wind speeds of 100 m/s (360 km/h) are common in zonal jets, and can reach as high as 620 kph (385 mph). Storms form within hours and can become thousands of km in diameter overnight. One storm, the Great Red Spot, has been raging since at least the late 1600s. The storm has been shrinking and expanding throughout its history; but in 2012, it was suggested that the Giant Red Spot might eventually disappear. Jupiter is composed primarily of gaseous and liquid matter. It is the largest of the gas giants, and like them, is divided between a gaseous outer atmosphere and an interior that is made up of denser materials. It’s upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules, and approx. 75% hydrogen and 24% helium by mass, with the remaining one percent consisting of other elements. The interior contains denser materials, such that the distribution is roughly 71% hydrogen, 24% helium and 5% other elements by mass. It is believed that Jupiter’s core is a dense mix of elements – a surrounding layer of liquid metallic hydrogen with some helium, and an outer layer predominantly of molecular hydrogen. The core has also been described as rocky, but this remains unknown as well. Jupiter has been visited by several spacecraft, including NASA's Pioneer 10 and Voyager spacecraft in the 1973 and 1980, respectively; and by the Cassini and New Horizons spacecraft more recently. Until the recent arrival of Juno, only the Galileo spacecraft has ever gone into orbit around Jupiter, and it was crashed into the planet in 2003 to prevent it from contaminating one of Jupiter's icy moons. In short, Jupiter is massive and has massive storms. But compared to the planets of the inner Solar System, is it significantly less dense. Jupiter also has the most moons in the Solar System, with 67 confirmed and named moons orbiting it. But it is estimated that as many as 200 may natural satellites may exist around the planet. Little wonder why this planet is named after the king of the gods. Saturn: Saturn is the second largest planet in the Solar System. With a mean radius of 58232±6 km, it is approximately 9.13 times the size of Earth. And at 5.6846×1026 kg, it is roughly 95.15 as massive. However, since it is a gas giant, it has significantly greater volume – 8.2713×1014 km3, which is equivalent to 763.59 Earths. The sixth most distant planet, Saturn orbits the Sun at an average distance of 9 AU (1.4 billion km; 869.9 million miles). Due to its slight eccentricity, the perihelion and aphelion distances are 9.022 (1,353.6 million km; 841.3 million mi) and 10.053 AU (1,513,325,783 km; 940.13 million mi), on average respectively. With an average orbital speed of 9.69 km/s, it takes Saturn 10,759 Earth days to complete a single revolution of the Sun. In other words, a single Cronian year is the equivalent of about 29.5 Earth years. However, as with Jupiter, Saturn’s visible features rotate at different rates depending on latitude, and multiple rotation periods have been assigned to various regions. As a gas giant, Saturn is predominantly composed of hydrogen and helium gas. With a mean density of 0.687 g/cm3, Saturn is the only planet in the Solar System that is less dense than water; which means that it lacks a definite surface, but is believed to have a solid core. This is due to the fact that Saturn’s temperature, pressure, and density all rise steadily toward the core. Standard planetary models suggest that the interior of Saturn is similar to that of Jupiter, having a small rocky core surrounded by hydrogen and helium with trace amounts of various volatiles. This core is similar in composition to the Earth, but more dense due to the presence of metallic hydrogen, which as a result of the extreme pressure. As a gas giant, the outer atmosphere of Saturn contains 96.3% molecular hydrogen and 3.25% helium by volume. Trace amounts of ammonia, acetylene, ethane, propane, phosphine and methane have been also detected in Saturn’s atmosphere. Like Jupiter, it also has a banded appearance, but Saturn’s bands are much fainter and wider near the equator. On occasion, Saturn’s atmosphere exhibits long-lived ovals that are thousands of km wide, similar to what is commonly observed on Jupiter. Whereas Jupiter has the Great Red Spot, Saturn periodically has what’s known as the Great White Spot (aka. Great White Oval). This unique but short-lived phenomenon occurs once every Saturnian year, roughly every 30 Earth years, around the time of the northern hemisphere’s summer solstice. The persisting hexagonal wave pattern around the north pole was first noted in the Voyager images. The sides of the hexagon are each about 13,800 km (8,600 mi) long (which is longer than the diameter of the Earth) and the structure rotates with a period of 10h 39m 24s, which is assumed to be equal to the period of rotation of Saturn’s interior. The south pole vortex, meanwhile, was first observed using the Hubble Space Telescope. These images indicated the presence of a jet stream, but not a hexagonal standing wave. These storms are estimated to be generating winds of 550 km/h, are comparable in size to Earth, and believed to have been going on for billions of years. In 2006, the Cassini space probe observed a hurricane-like storm that had a clearly defined eye. Such storms had not been observed on any planet other than Earth – even on Jupiter. Of course, the most amazing feature of Saturn is its rings. These are made of particles of ice ranging in size from a grains of sand to the size of a car. Some scientists think the rings are only a few hundred million years old, while others think they could be as old as the Solar System itself. Saturn has been visited by spacecraft 4 times: Pioneer 11, Voyager 1 and 2 were just flybys, but Cassini has actually gone into orbit around Saturn and has captured thousands of images of the planet and its moons. And speaking of moons, Saturn has a total of 62 moons discovered (so far), though estimates indicate that it might have as many as 150. So like Jupiter, Saturn is a massive gas giant that experiences some very interesting weather patterns. It also has lots of moons and has very low density. But what really makes Saturn stand out is its impressive ring system. Whereas every gas and ice giant has one, Saturn's is visible to the naked eye and very beautiful to behold! Uranus: Next comes Uranus, the seventh planet from the Sun. With a mean radius of approximately 25,360 km and a mass of 8.68 × 1025 kg, Uranus is approximately 4 times the sizes of Earth and 63 times its volume. However, as a gas giant, its density (1.27 g/cm3) is significantly lower; hence, it is only 14.5 as massive as Earth. The variation of Uranus’ distance from the Sun is also greater than that any other planet (not including dwarf planets or plutoids). Essentially, the gas giant’s distance from the Sun varies from 18.28 AU (2,735,118,100 km) at perihelion to 20.09 AU (3,006,224,700 km) at aphelion. At an average distance of 3 billion km from the Sun, it takes Uranus roughly 84 years (or 30,687 days) to complete a single orbit of the Sun. The standard model of Uranus’s structure is that it consists of three layers: a rocky (silicate/iron–nickel) core in the center, an icy mantle in the middle and an outer envelope of gaseous hydrogen and helium. Much like Jupiter and Saturn, hydrogen and helium account for the majority of the atmosphere – approximately 83% and 15% – but only a small portion of the planet’s overall mass (0.5 to 1.5 Earth masses). The third most abundant element is methane ice (CH4), which accounts for 2.3% of its composition and which accounts for the planet’s aquamarine or cyan coloring. Trace amounts of various hydrocarbons are also found in the stratosphere of Uranus, which are thought to be produced from methane and ultraviolent radiation-induced photolysis. They include ethane (C2H6), acetylene (C2H2), methylacetylene (CH3C2H), and diacetylene (C2HC2H). In addition, spectroscopy has uncovered carbon monoxide and carbon dioxide in Uranus’ upper atmosphere, as well as the presence icy clouds of water vapor and other volatiles, such as ammonia and hydrogen sulfide. Because of this, Uranus and Neptune are considered a distinct class of giant planet – known as “Ice Giants” – since they are composed mainly of heavier volatile substances.

The rotational period of the interior of Uranus is 17 hours, 14 minutes. As with all giant planets, its upper atmosphere experiences strong winds in the direction of rotation. Hence its weather systems are also broken up into bands that rotate around the planet, which are driven by internal heat rising to the upper atmosphere.

As a result, winds on Uranus can reach up to 900 km/h (560 mph), creating massive storms like the one spotted by the Hubble Space Telescope in 2012. Similar to Jupiter’s Great Red Spot, this “Dark Spot” was a giant cloud vortex that measured 1,700 kilometers by 3,000 kilometers (1,100 miles by 1,900 miles).

One unique feature of Uranus is that it rotates on its side. Whereas all of the Solar System’s planets are tilted on their axes to some degree, Uranus has the most extreme axial tilt of 98°. This leads to the radical seasons that the planet experiences, not to mention an unusual day-night cycle at the poles. At the equator, Uranus experiences normal days and nights; but at the poles, each experience 42 Earth years of day followed by 42 years of night.

Uranus was the first planet to be discovered with a telescope; it was first recognized as a planet in 1781 by William Herschel. Beyond Earth-based observations, only one spacecraft (Voyager 2) has ever studied Uranus up close. It passed by the planet in 1986, and captured the first close images. Uranus has 27 known moons. Uranus' special nature comes through in its natural beauty, its intense weather, its ring system and its impressive array of moons. And it's compositions, being an "ice" giant, is what gives its aquamarine color. But perhaps mist interesting is its sideways rotation, which is unique among the Solar planets. Neptune:

Neptune is the 8th and final planet in the Solar System, orbiting the Sun at a distance of 29.81 AU (4.459 x 109 km) at perihelion and 30.33 AU (4.537 x 109 km) at aphelion. With a mean radius of 24,622 ± 19 km, Neptune is the fourth largest planet in the Solar System and four times as large as Earth. But with a mass of 1.0243×1026 kg – which is roughly 17 times that of Earth – it is the third most massive, outranking Uranus.

Neptune takes 16 h 6 min 36 s (0.6713 days) to complete a single sidereal rotation, and 164.8 Earth years to complete a single orbit around the Sun. This means that a single day lasts 67% as long on Neptune, whereas a year is the equivalent of approximately 60,190 Earth days (or 89,666 Neptunian days). Due to its smaller size and higher concentrations of volatiles relative to Jupiter and Saturn, Neptune (much like Uranus) is often referred to as an “ice giant” – a subclass of a giant planet. Also like Uranus, Neptune’s internal structure is differentiated between a rocky core consisting of silicates and metals; a mantle consisting of water, ammonia and methane ices; and an atmosphere consisting of hydrogen, helium and methane gas. The core of Neptune is composed of iron, nickel and silicates, with an interior model giving it a mass about 1.2 times that of Earth. The pressure at the center is estimated to be 7 Mbar (700 GPa), about twice as high as that at the center of Earth, and with temperatures as high as 5,400 K. At a depth of 7000 km, the conditions may be such that methane decomposes into diamond crystals that rain downwards like hailstones. Because Neptune’s axial tilt (28.32°) is similar to that of Earth (~23°) and Mars (~25°), the planet experiences similar seasonal changes. Combined with its long orbital period, this means that the seasons last for forty Earth years. Also owing to its axial tilt being comparable to Earth’s is the fact that the variation in the length of its day over the course of the year is not any more extreme than it on Earth. Just like Jupiter and Saturn, Neptune has bands of storms that circle the planet. Astronomers have clocked winds on Neptune traveling at 2,100 km/hour, which is believed to be due to Neptune's cold temperatures - which may decrease the friction in the system, During its 1989 flyby, NASA’s Voyager 2 spacecraft discovered the Great Dark Spot on Neptune. Similar to Jupiter’s Great Red Spot, this is an anti-cyclonic storm measuring 13,000 km x 6,600 km across. A few years later, however, the Hubble Space Telescope failed to see the Great Dark Spot, but it did see different storms. This might mean that storms on Neptune don’t last as long as they do on Jupiter or even Saturn. The more active weather on Neptune might be due, in part, to its higher internal heat. Although Neptune is much more distant than Uranus from the Sun, receiving 40% less sunlight, temperatures on the surface of the two planets are roughly similar. In fact, Neptune radiates 2.61 times as much energy as it receives from the Sun. This is enough heat to help drive the fastest winds in the Solar System. Neptune is the second planet discovered in modern times. It was discovered at the same time by both Urbain Le Verrier and John Couch Adams. Neptune has only ever been visited by one spacecraft, Voyager 2, which made a fly by in August, 1989. Neptune has 13 known moons. Th largest and most famous of these is Triton, which is believed to be a former KBO that was captured by Neptune's gravity. So much like Uranus, Neptune has a ring system, some intense weather patterns, and an impressive array of moons. Also like Uranus, Neptune's composition allows for its aquamarine color; except that in Neptune's case, this color is more intense and vivid. In addition, Neptune experiences some temperature anomalies that are yet to be explained. And let's not forgt the raining diamonds! And those are the planets in the Solar System thank you for joining the tour! Unfortunately, Pluto isn't a planet any more, hence why it was not listed. We know, we know, take it up with the IAU! We have written many interesting articles about the Solar System here at Universe Today. Here's the Solar System GuideWhat is the Solar System?, Interesting Facts About the Solar System, What Was Here Before the Solar System?, How Big is the Solar System?, and Is the Solar System Really a Vortex? If you'd like more information on the Solar System, visit the Nine Planets, and Solar Views. We have recorded a whole series of podcasts about the Solar System at Astronomy Cast. Sources:

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Categories: space

Physicists Maybe, Just Maybe, Confirm the Possible Discovery of 5th Force of Nature

Universe Today - 17 August, 2016 - 19:11

For some time, physicists have understood that all known phenomena in the Universe are governed by four fundamental forces. These include weak nuclear force, strong nuclear force, electromagnetism and gravity. Whereas the first three forces of are all part of the Standard Model of particle physics, and can be explained through quantum mechanics, our understanding of gravity is dependent upon Einstein's Theory of Relativity. Understanding how these four forces fit together has been the aim of theoretical physics for decades, which in turn has led to the development of multiple theories that attempt to reconcile them (i.e. Super String Theory, Quantum Gravity, Grand Unified Theory, etc). However, their efforts may be complicated (or helped) thanks to new research that suggests there might just be a fifth force at work. In a paper that was recently published in the journal Physical Review Letters, a research team from the University of California, Irvine explain how recent particle physics experiments may have yielded evidence of a new type of boson. This boson apparently does not behave as other bosons do, and may be an indication that there is yet another force of nature out there governing fundamental interactions. As Jonathan Feng, a professor of physics & astronomy at UCI and one of the lead authors on the paper, said: “If true, it’s revolutionary. For decades, we’ve known of four fundamental forces: gravitation, electromagnetism, and the strong and weak nuclear forces. If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe, with consequences for the unification of forces and dark matter.” The efforts that led to this potential discovery began back in 2015, when the UCI team came across a study from a group of experimental nuclear physicists from the Hungarian Academy of Sciences Institute for Nuclear Research. At the time, these physicists were looking into a radioactive decay anomaly that hinted at the existence of a light particle that was 30 times heavier than an electron. In a paper describing their research, lead researcher Attila Krasznahorka and his colleagues claimed that what they were observing might be the creation of "dark photons". In short, they believed that they might have at last found evidence of Dark Matter, the mysterious, invisible mass that makes up about 85% of the Universe's mass. This report was largely overlooked at the time, but gained widespread attention earlier this year when Prof. Feng and his research team found it and began assessing its conclusions. But after studying the Hungarian teams results and comparing them to previous experiments, they concluded that the experimental evidence did not support the existence of dark photons. Instead, they proposed that the discovery could indicate the possible presence of a fifth fundamental force of nature. These findings were published in arXiv in April, which was followed-up by a paper titled "Particle Physics Models for the 17 MeV Anomaly in Beryllium Nuclear Decays", which was published in PRL this past Friday. Essentially, the UCI team argue that instead of a dark photon, what the Hungarian research team might have witnessed was the creation of a previously undiscovered boson - which they have named the "protophobic X boson". Whereas other bosons interact with electrons and protons, this hypothetical boson interacts with only electrons and neutrons, and only at an extremely limited range. This limited interaction is believed to be the reason why the particle has remained unknown until now, and why the adjectives "photobic" and "X" are added to the name. “There’s no other boson that we’ve observed that has this same characteristic," said Timothy Tait, a professor of physics & astronomy at UCI and the co-author of the paper. "Sometimes we also just call it the ‘X boson,’ where ‘X’ means unknown.” If such a particle does exist, the possibilities for research breakthroughs could be endless. Feng hopes it could be joined with the three other forces governing particle interactions (electromagnetic, strong and weak nuclear forces) as a larger, more fundamental force. Feng also speculated that this possible discovery could point to the existence of a "dark sector" of our universe, which is governed by its own matter and forces. “It’s possible that these two sectors talk to each other and interact with one another through somewhat veiled but fundamental interactions,” he said. “This dark sector force may manifest itself as this protophopic force we’re seeing as a result of the Hungarian experiment. In a broader sense, it fits in with our original research to understand the nature of dark matter.” If this should prove to be the case, then physicists may be closer to figuring out the existence of dark matter (and maybe even dark energy), two of the greatest mysteries in modern astrophysics. What's more, it could aid researchers in the search for physics beyond the Standard Model - something the researchers at CERN have been preoccupied with since the discovery of the Higgs Boson in 2012. But as Feng notes, we need to confirm the existence of this particle through further experiments before we get all excited by its implications: "The particle is not very heavy, and laboratories have had the energies required to make it since the ’50s and ’60s. But the reason it’s been hard to find is that its interactions are very feeble. That said, because the new particle is so light, there are many experimental groups working in small labs around the world that can follow up the initial claims, now that they know where to look." As the recent case involving CERN - where LHC teams were forced to announce that they had not discovered two new particles - demonstrates, it is important not to count our chickens before they are roosted. As always, cautious optimism is the best approach to potential new findings. Further Reading: University of California, Irvine

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Categories: space

Stairway to Heaven! – Boeing Starliner Crew Access Arm’s ‘Awesome’ Launch Pad Installation

Universe Today - 17 August, 2016 - 18:48

CAPE CANAVERAL AIR FORCE STATION, FL — A new ‘Stairway to Heaven’ which American astronauts will soon stride along as “the last place on Earth” departure point aboard our next generation of human spaceships, was at long last hoisted into place at the ULA Atlas rocket launch pad on Florida’s Space Coast on Monday Aug 15, at an “awesome” media event witnessed by space journalists including Universe Today. "This is awesome," Chris Ferguson, a former shuttle commander who is now Boeing's deputy program manager for the company's Commercial Crew Program told Universe Today in an exclusive interview at the launch pad - after workers finished installing the spanking new Crew Access Arm walkway for astronauts leading to the hatch of Boeing’s Starliner ‘Space Taxi.’ Starliner will ferry crews to and from the International Space Station (ISS) as soon as 2018. “It’s great to see the arm up there,” Ferguson elaborated to Universe Today. “I know it’s probably a small part of the overall access tower. But it’s the most significant part!” “We used to joke about the 195 foot level on the shuttle pad as being ‘the last place on Earth.” “This will now be the new ‘last place on Earth’! So we are pretty charged up about it!” Ferguson gushed. Under hot sunny skies portending the upcoming restoration of America’s ability to once again launch American astronauts from American soil when American rockets ignite, the newly constructed 50-foot-long, 90,000-pound ‘Crew Access Arm and White Room’ was lifted and mated to the newly built ‘Crew Access Tower’ at Space Launch Complex-41 (SLC-41) on Monday morning, Aug. 15. “We talked about how the skyline is changing here and this is one of the more visible changes.” The Boeing CST-100 Starliner crew capsule stacked atop the venerable United Launch Alliance (ULA) Atlas V rocket at pad 41 on Cape Canaveral Air Force Station in Florida will launch crews to the massive orbiting science outpost continuously soaring some 250 miles (400 km) above Earth. Space workers, enthusiasts and dreamers alike have been waiting years for this momentous day to happen. And I was thrilled to observe all the action firsthand along with the people who made it happen from NASA, United Launch Alliance, Boeing, the contractors - as well as to experience it with my space media colleagues. “All the elements that we talked about the last few years are now reality,” Ferguson told me. Attaching the access arm is vital and visual proof that at long last America means business and that a renaissance in human spaceflight will commence in some 18 months or less when commercially built American crew capsules from Boeing and SpaceX take flight to the heavens above - and a new space era of regular, robust and lower cost space flights begins. It took about an hour for workers to delicately hoist the gleaming grey steel and aluminum white ‘Stairway to Heaven’ by crane into place at the top of the tower - at one of the busiest launch pads in the world! It’s about 130 feet above the pad surface since it’s located at the 13th level of the tower. The install work began at about 7:30 a.m. EDT as we watched a work crew lower a giant grappling hook and attach cables. Then they carefully raised the arm off the launch pad surface by crane. The arm had been trucked to the launch pad on Aug. 11. The tower itself is comprised of segmented tiers that were built in segments just south of the pad. They were stacked on the pad over the past few months - in between launches. Altogether they form a nearly 200-foot-tall steel structure. Another crew stationed in the tower about 160 feet above ground waited as the arm was delicately craned into the designated notch. The workers then spent several more hours methodically bolting and welding the arm to the tower to finish the assembly process. Indeed Monday’s installation of the Crew Access Arm and White Room at pad 41 basically completes the construction of the first new Crew Access Tower at Cape Canaveral Air Force Station since the Apollo moon landing era of the 1960s. “It is the first new crew access structure at the Florida spaceport since the space shuttle's Fixed Service Structures were put in place before Columbia's first flight in 1981,” say NASA officials. Overall the steel frame of the massive tower weighs over a million pounds. For perspective, destination ISS now weighs in at about a million pounds in low Earth orbit. Construction of the tower began about 18 months ago. "You think about when we started building this 18 months ago and now it's one of the most visible changes to the Cape's horizon since the 1960s," said Ferguson at Monday’s momentous media event. “It's a fantastic day." The White Room is an enclosed area at the end of the Crew Access Arm. It big enough for astronauts to make final adjustments to their suits and is spacious enough for technicians to assist the astronauts climbing aboard the spacecraft and get tucked into their seats in the final hours before liftoff. "You have to stop and celebrate these moments in the craziness of all the things we do,” said Kathy Lueders, manager of NASA’s Commercial Crew Program, at the event. “It’s going to be so cool when our astronauts are walking out across this access arm to get on the spacecraft and go to the space station.” The Crew Access Arm was built by Saur at NASA’s nearby off site facility at Oak Hill. And when Starliner takes flight it will hearken back to the dawn of the Space Age. "John Glenn was the first to fly on an Atlas, now our next leap into the future will be to have astronauts launch from here on Atlas V," said Barb Egan, program manager for Commercial Crew for ULA. Boeing is manufacturing Starliner in what is officially known as Boeing’s Commercial Crew and Cargo Processing Facility (C3PF) at the Kennedy Space Center in Florida under contract with NASA’s Commercial Crew Program (CCP). The Boeing CST 100 Starliner is one of two private astronaut capsules - along with the SpaceX Crew Dragon - being developed under a CCP commercial partnership contract with NASA to end our sole reliance on Russia for crew launches back and forth to the International Space Station (ISS). The goal of NASA’s Commercial Crew Program since its inception in 2010 is to restore America’s capability to launch American astronauts on American rockets from American soil to the ISS, as soon as possible. Furthermore when the Boeing Starliner and SpaceX Crew Dragon become operational the permanent resident ISS crew will grow to 7 - enabling a doubling of science output aboard the science laboratory. This significant growth in research capabilities will invaluably assist NASA in testing technologies and human endurance in its agency wide goal of sending humans on a ‘Journey to Mars’ by the 2030s with the mammoth Space Launch System (SLS) rocket and Orion deep space capsule concurrently under full scale development by the agency. The next key SLS milestone is a trest firing of the RS-25 main engines at NASA Stennis this Thursday, Aug. 18 - watch for my onsite reports! Boeing was awarded a $4.2 Billion contract in September 2014 by NASA Administrator Charles Bolden to complete development and manufacture of the CST-100 Starliner space taxi under the agency’s Commercial Crew Transportation Capability (CCtCap) program and NASA’s Launch America initiative. Since the retirement of NASA’s space shuttle program in 2011, the US was been 100% dependent on the Russian Soyuz capsule for astronauts rides to the ISS at a cost exceeding $70 million per seat. When will Ferguson actually set foot inside the walkway? “I am hoping to get up there and walk through there in a couple of weeks or so when it’s all strapped in and done. I want to see how they are doing and walk around.” How does the White Room fit around Starliner and keep it climate controlled? “The end of the white room has a part that slides up and down and moves over and slides on top of the spacecraft when it’s in place.” “There is an inflatable seal that forms the final seal to the spacecraft so that you have all the appropriate humidity control and the purge without the Florida atmosphere inside the crew module,” Ferguson replied. Boeing and NASA are targeting Feb. 2018 for launch of the first crewed orbital test flight on the Atlas V rocket. The Atlas will be augmented with two solid rocket motors on the first stage and a dual engine Centaur upper stage. How confident is Ferguson about meeting the 2018 launch target? “The first crew flight is scheduled for February 2018. I am confident.” Ferguson responded. “And we have a lot of qualification to get through between now and then. But barring any large unforeseen issues we can make it.” Stay tuned here for Ken's continuing Earth and planetary science and human spaceflight news. Ken Kremer

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Categories: space

Beyond Neptune, A Chunk Of Ice Is Orbiting The Sun In The Wrong Direction

Universe Today - 16 August, 2016 - 21:33

Beyond the orbit of Neptune, the farthest recognized-planet from our Sun, lies the mysteries population known as the Trans-Neptunian Object (TNOs). For years, astronomers have been discovering bodies and minor planets in this region which are influenced by Neptune's gravity, and orbit our Sun at an average distance of 30 Astronomical Units. In recent years, several new TNOs have been discovered that have caused us to rethink what constitutes a planet, not to mention the history of the Solar System. The most recent of these mystery objects is called "Niku", a small chunk of ice that takes its name for the Chinese word for "rebellious". And while many such objects exist beyond the orbit of Neptune, it is this body's orbital properties that really make it live up to the name! In a paper recently submitted to arXiv, the international team of astronomers that made the discovery explain how they found the TNO using the Panoramic Survey Telescope and Rapid Response System 1 Survey (Pan-STARRS 1). Measuring just 200 km (124 miles) in diameter, this object's orbit is tilted 110° to the plane of the Solar system and orbits the Sun backwards.

Ordinarily, when planetary systems form, angular momentum forces everything to spin in the same direction. Hence why, when viewed from the celestial north pole, all the objects in our Solar System appear to be orbiting the Sun in a counter-clockwise direction. So when objects orbit the Sun in the opposite direction, an outside factor must be at play.

What's more, the team compared the orbit of Niku with other high-inclination TNOs and Centaurs, and noticed that they occupy a common orbital plane and experience a clustering effect. As Dr. Matthew J. Holman - a professor at the Harvard-Smithsonian Center for Astrophysics and one of the researchers on the team - told Universe Today via email:

"The orbit of Niku is unusual in that it is nearly perpendicular to the plane of the Solar System.  More than that, it is orbiting in the opposite direction of most Solar System bodies. Furthermore, there are a few bodies that share the same or orbital plane, with some orbiting prograde and some orbiting retrograde. That was unexpected."

One possibility, which the team has already considered, was that this mysterious orbital pattern might be evidence of the much sought-after Planet Nine. This hypothetical planet, which is believed to exist at the outer edge of our Solar System (20 times further from our Sun than Neptune), if it exists, is also thought to be 10 times the size of the Earth.

"Planet Nine seems to be gravitationally influencing another nearby population of bodies that are also orbiting nearly perpendicular to the plane of the solar system," said Holman, "but those objects have much larger orbits that also come closer to sun at their closest approach. The similarity (perpendicular) nature of Niku's orbit to that of the more distant population hints at a connection."

Establishing such a connection based on the orbits of distant objects is certainly tempting, especially since no direct evidence of Planet Nine has been obtained yet. However, upon further analysis, the team concluded that Niku is too close to the rest of the Solar System for its orbit to be effected by Planet Nine.

In addition, the orbits of the clustered objects that circle the sun backwards along the same 110-degree plane path was seen as a further indication that something else is probably at work. Then again, it may very well be that there is a giant planet out there, and that it's influence is mitigated by other factors we are not yet aware of.

"The population of objects in Niku-like orbits is not long-term stable," said Holman. "We hoped that adding the gravitational influence of an object like Planet Nine might stabilize their orbits, but that turned out not to be the case. We are NOT ruling out Planet Nine, but we are not finding any direct evidence for it, at least with this investigation."

So for the time being, it looks like Planet Nine enthusiasts are going to have to wait for some other form of confirmation. But as Konstantin Batyagin - the Caltech astronomer who announced findings that hinted at Planet Nine earlier this year - was quoted as saying, this discovery is yet another step in the direction of a more complete understanding of the outer Solar System:

“Whenever you have some feature that you can’t explain in the outer solar system, it’s immensely exciting because it’s in some sense foreshadowing a new development. As they say in the paper, what they have right now is a hint. If this hint develops into a complete story that would be fantastic.”

Whatever the cause of Niku's strange orbit (or those TNOs that share its orbital pattern) may be, it is clear that there is more going on in the outer Solar System than we thought. And with every new discovery, and every new object catalogued by astronomers, we are bettering our understanding of the dynamics that are at work out there.

In the meantime, perhaps we'll just need to send some additional missions out that way. We have nothing to lose but our preconceived notions! And be sure to enjoy this video about this latest find, courtesy of New Scientist: Further Reading: arXiv

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Categories: space

Prof. Lubin Wants to Send Our Digital Selves to the Stars

Universe Today - 16 August, 2016 - 17:10

Setting foot on a distant planet... we've all dreamed about it at one time or another. And it has been a staple of science fiction for almost a century. Engage the warp dive, spool up the FLT, open a wormhole, or jump into the cryochamber. Next stop, Alpha Centauri (or some other star)! But when it comes to turning science fiction into science fact, there are certain unfortunate realities we have to contend with. For starters, none of the technology for faster-than-light travel exists! Second, sending crewed mission to even the nearest planets is a very expensive and time consuming endeavor. But thanks to ongoing developments in the fields of miniaturization, electronics and direct-energy, it might be possible to send tiny spacecraft to distant stars in a single lifetime, which could carry something of humanity along with them. Such is the hope of Professor Philip Lubin and Travis Bradshears, the founders of "Voices of Humanity". For people familiar with directed-energy concepts, the name Philip Lubin should definitely ring a bell. A professor from the University of California, Santa Barbara (UCSB), he is also the mind behind the NASA-funded Directed Energy Propulsion for Interstellar Exploraiton (DEEP-IN) project, and the Directed Energy Interstellar Study. These projects seek to use laser arrays and large sails to achieve relativistic flight for the sake of making interstellar missions a reality. Looking beyond propulsion and into the realm of public participation in space exploration, Prof. Lubin and Bradshears (an engineering and physics student from the University of California, Berkeley) came together to launch Voices of Humanity (VoH) in 2015. Inspired by their work with NASA, this Kickstarter campaign aims to create the world's first "Space Time Capsule". Intrinsic to this is the creation of a Humanity Chip, a custom semiconductor memory device that can be attached to the small, wafer-scale spacecraft that are part of DEEP-IN and other directed-energy concepts. This chip will contain volumes of data, including tweets, media files, and even the digital DNA records of all those who want to take part in the mission. As Professor Lubin told Universe Today in a phone interview: “We wanted to put on board some part of humanity. We couldn’t shrink ray people down, so Travis and I brainstormed and thought that the next best thing would be to allow people to become digital astronauts. We wanted to pave the way for interstellar missions where we could send the essence of humanity to the stars - "Emissaries of the Earth", if you will. We wanted to pave the way for that.” This digital archive would be similar to the Golden Record that was placed on the Voyager probes, but would be much more sophisticated. Taking advantage of all the advances made in computing, electronics and data storage in recent decades, it would contain many millions of times the data, but comprise a tiny fraction of the volume. In fact, as Lupin explained, the state of technology today allows us to create a digital archive that would be about the same size a fingernail, and which would require no more than a single gram of mass to be allocated on a silicon wafer-ship. And while such a device is not the same as sending astronauts on interstellar voyages to explore other planets, it does allow humanity to send something of itself. “We now have the technology to put a message from everyone on Earth onto a small piece of a tiny spacecraft," said Lupin. "We want to begin today, and not just for the future, by putting information onto anything that is launched from Earth. We are the point technologically, at this moment, that we could put a small portion of humanity on this spacecraft." In essence, human beings would be able to create the interstellar equivalent of a "Baby on Board" sticker, except for humanity instead. This sticker would be no larger than a postage stamp, and could be mounted on every craft to leave Earth in the near future. In essence, all missions departing from Earth could have "Humanity on Board". The plan is to launch their first chip - Humanity Chip 1.0 - into Low Earth Orbit (LEO) in 2017. This will be followed by the creation of Humanity Chip 2.0, which take advantage of the developments that will have occurred by next year. Eventually, they hope that Humanity Chips will be a part of missions that increase in distance from Earth, eventually culminating in a mission to interstellar space. While there are no deep-space missions ready to go just yet, several concepts are on the table for interplanetary missions that will rely on wafer-scale spacecraft (like NASA's DEEP-IN concept). If their Kickstarter campaign succeeds in raising the $30,000 necessary to create a Humanity Chip, Prof. Lubin and Bradshears also hope to create a "Black Hole Chip", where participants will be able to record their "less than happy" thoughts as part of the data, which will then be sent off into space forever. They also have a stretch goal in mind, known as the "Beam Me Up" objective. In the event that their campaign is able to raise $100,000, they will use the funds to create a ground-based laser array that will beam a package of encoded data towards a target destination in space. As of the penning of this article, Prof. Lubin and Bradshears have raised a total of $5,656 towards their goal of $30,000. The campaign kicked off earlier this month and will remain open for another 22 days. So if you're interested in contributing to Humanity Chip 1.0, or becoming an "Emissary of the Earth", there's still plenty of time. In addition to his work with NASA, Prof. Lubin is also responsible for the UCSB's Directed Energy System for Targeting of Asteroids and ExploRation (DE-STAR)  project, a proposed system that would use directed energy (i.e. big lasers!) to deflect asteroids, comets, and other near-Earth objects (NEOs) that could pose a risk to planet Earth. And, in a recent article titled "The Search for Directed Intelligence"- which appeared in the March 2016 issue of  REACH – Reviews in Human Space Exploration - Lupin indicated that advances in directed-energy applications might also help in the search for extra-terrestrial intelligence. Essentially, by looking for for sources of directed energy systems, he claims, we might be able to find our way to other civilizations. It is an exciting age, where advances in telecommunications and electronics are allowing us to overcome the vast distances involved in space travel. In the future, astronauts may rely on robotic explorers and fast-as-light communications to explore distant worlds (a process known as telexploration). And with a digital archive on board, we will be able to send personal greetings to any life that may already exist there. For those who would say "sharing personal information with extra-terrestrials is a bad idea", I would remind them that they (probably) don't have access to Twitter or our financial records. All the same, it might be wise not to include your Social Security (or Social Insurance) number in the recordings, or any other personal data you wouldn't share with strangers! And who knows? Someday, we may start colonizing other planets by sending our DNA there direct. The truth is always stranger than fiction, after all! And be sure to check out this video produced by Voices for Humanity: Further Reading: Voices of Humanity

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Categories: space

One Year to the 2017 Total Solar Eclipse

Universe Today - 16 August, 2016 - 09:49

One. More. Year. Quick; where will you be this time next year on August 21st, 2017? We're now just one year out this weekend from a fine total solar eclipse gracing the United States from coast to coast. If you think one year out is too early to start planning, well, umbraphiles (those who chase the shadow of the Moon worldwide) have been planning to catch this one now for over a decade. Get set for the Great American Eclipse. The last time a total solar eclipse made landfall over a U.S. state was Hawaii on July 11th, 1991, and the path of totality hasn't touched down over the contiguous 'Lower 48' United States since February 26th, 1979. And you have to go all the way back over nearly a century to June 8th, 1918 to find an eclipse that exclusively crossed the United States from the Pacific to the Atlantic Coast. Totality for the August 21st, 2017 eclipse crosses over many major cities, including Columbia South Carolina, Nashville, St. Louis and Salem, Oregon. The inner shadow of the Moon touches on 15 states as it races across the U.S. in just over an hour and a half. The length of totality is about 2 minutes in duration as the shadow makes landfall near Lincoln City, Oregon, reaches a maximum duration of 2 minutes, 42 seconds very near Carbondale, Illinois, and shrinks back down to 2 minutes and 35 seconds as the shadow heads back out to sea over Charleston, South Carolina. The eclipse will be a late morning affair in the northwest, occurring at high noon over western Nebraska, and early afternoon to the east. 'Getting your ass to totality,' is a must. “But I've seen a partial solar eclipse,” is a common refrain, “aren't they all the same?” Nope. We witnessed the May 10th, 1994 annular eclipse from the shores of Lake Erie, and can tell you that even less than 1% of the Sun's intensity is still pretty bright, a steely blue luminosity equivalent to a cloudy day. We crisscrossed the United States along the eclipse path back in 2014, chronicling preparations in towns such as Columbia and Hopkinsville, Kentucky. Last minute accommodation is already tough to come by, even one year out. Cabins in the Land Between the Lakes region near Paducah, Kentucky, for example, were booked full as soon as the August 21st date became available. Think Mardi Gras and DragonCon, rolled into one. Hopkinsville also has an annual Roswell-style UFO-fest on the same date, celebrating the 1955 Kelly-Hopkinsville UFO incident. Will it be 'umbraphiles versus aliens?' Out west, enticing locales include the Grand Teton National Park and Jackson Hole, Wyoming and the northern edge of the Craters of the Moon National Monument site in Idaho. It's also worth noting that the western United States is a better bet cloud cover-wise, as afternoon summer thundershowers tend to be the norm for the southeast during late August. Millions live within an easy day drive of the eclipse path, and it happens during prime camping season, to boot. The annual Sturgess motorcycle rally held near Rapid City, South Dakota is just one week prior to totality, and bikers returning from the pilgrimage southward could easily stop to greet the Earth's shadow on the road home. 2017 Eclipse Panorama from Michael Zeiler on Vimeo. There's been talk that Cosmoquest may mount an eclipse expedition based out of Nashville, Tennessee (more to come on that). Maintaining mobility is the best bet. Our master plan is to return to the States a week or so prior, rent a camper van from Vegas, and head northward. Like millions of Americans, this will be our first total solar eclipse, and the event promises to spark a whole new generation of umbraphiles. And stick around just seven more years, and totality will again cross the United States on August 8th, 2024 from the southwest to the northeast. The Illinois, Missouri and Kentucky tri-state region sees this eclipse as well. This one is special for us, as it crosses over our hometown of Presque Isle, Maine. I remember looking up the next total solar eclipse over northern Maine as a kid, way back when, and figuring out just how old I would be. The top of Mount Katahdin and selected sites along the Maine Solar System model would all be choice locales to view this one. Check out this great old vid of the aforementioned 1979 eclipse over the U.S.: We also plan on taking the veteran eclipse-chaser's mantra of 'experience your first eclipse; but photograph your second one.' to heart. Lots of fascinating projects are afoot leading up to the 2017 total solar eclipse, including The Eclipse MegaMovie Project to produce a complete video documentary of the eclipse path, plans by a student group to fly and observe the eclipse from balloons during totality, proposals to replicate famous eclipse experiments and more. It's also worth noting that the bright star Regulus will sit just one degree from the Sun during totality... perhaps someone will manage to measure its deflection via General Relativity in a manner similar to Sir Arthur Eddington's famous 1919 observation? Unlike the paths of most eclipses, which seem to have an affinity for wind-swept tundra or remote swaths of desert, this one is sure to draw in the 'astronomy-curious' and may just be the most witnessed total solar eclipse in history. Here's some eclipse tales and facts to ponder leading up to totality. If you caught the August 11th, 1999 eclipse across Europe, then you saw the last eclipse in the same saros series 145. If you caught the eclipse before that in the same series on July 31st, 1981 across northeast Asia, then you'll complete a 54 year long triple-saros period after seeing next summer's eclipse, known as an exeligmos. This cycle also brings the eclipse path very nearly back around to the same longitude. The Sun is about 400 times larger than the Moon in diameter, but the Moon is 400 times closer. We've actually heard this fact tossed out as evidence for intelligent design, though it's just a happy celestial circumstance of our present era. In fact, annular eclipses are now slightly more common than totals in our current epoch, and will continue to become more so as the Moon slowly recedes from the Earth. Just under a billion years ago, the very first annular eclipse of the Sun as seen from the Earth occurred, and 1.4 billion years hence, the Earth will witness one last brief total eclipse. But you won't have to wait that long. Don't miss the greatest show in the universe next August! -Check out Michael Zeiler's (@EclipseMaps) 10-foot long strip map of the entire eclipse path. -Eclipses, both lunar and solar have played a role in history as well. -Curious about eclipses in time and space? Read our eclipse-fueled sci-fi tales, Exeligmos, The Syzygy Gambit and Shadowfall, with more to come!

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Categories: space

How Fast Can Stars Spin?

Universe Today - 11 July, 2016 - 22:48

Everything in the Universe is spinning. Spinning planets and their spinning moons orbit around spinning stars, which orbit spinning galaxies. It’s spinning all the way down.

Consider that fiery ball in the sky, the Sun. Like all stars, our Sun rotates on its axis. You can’t tell because staring at the Sun long enough will permanently damage your eyeballs. Instead you can use a special purpose solar telescope to observe sunspots and other features on the surface of the Sun. And if you track their movements, you’ll see that the Sun’s equator takes 24.47 days to turn once on its axis. Unlike its slower poles which take 26.24 days to turn.

The Sun isn’t a solid ball of rock, it’s a sphere of hot plasma, so the different regions can complete their rotation at different rates. But it rotates so slowly that it’s an almost perfect sphere.

If you were standing on the surface of the Sun, which you can’t, of course, you would be whipping around at 7,000 km/h. That sounds fast, but just you wait.

How does that compare to other stars, and what’s the fastest that a star can spin?

Achenar rotates much faster than our Sun. It is located at the lower right of the constellation Eridanus.

A much faster spinning star is Achenar, the tenth brightest star in the sky, located 139 light-years away in the constellation of Eridanus. It has about 7 times the mass of the Sun, but it spins once on its axis every 2 days. If you could see Achenar up close, it would look like a flattened ball. If you measured it from pole to pole, it would be 7.6 Suns across, but if you measured across the equator, it would be 11.6 Suns across.

If you were standing on the surface of Achenar, you’d be hurtling through space at 900,000 km/h.

The very fastest spinning star we know of is the 25 solar mass VFTS 102, located about 160,000 light-years away in the Large Magellanic Cloud’s Tarantula Nebula – a factory for massive stars.

If you were standing on the surface of VFTS 102, you’d be moving at 2 million km/h.

In fact, VFTS 102 is spinning so quickly, it can just barely keep itself together. Any faster, and the outward centripetal force would overcome the gravity holding its guts in, and it would tear itself apart. Perhaps that’s why we don’t see any spinning faster; because they couldn’t handle the speed. It appears that this is the fastest that stars can spin.

This is an artist’s concept of VFTS 102, the fastest rotating star found to date. Credit: NASA, ESA, and G. Bacon (STScI)

One other interesting note about VFTS 102 is that it’s also hurtling through space much faster than the stars around it. Astronomers think it was once in a binary system with a partner that detonated as a supernova, releasing it into space like a catapult.

Not only stars can spin. Dead stars can spin too, and they take this to a whole other level.

Neutron stars are what you get when a star with much more mass than the Sun detonates as a supernova. Suddenly you’ve got a stellar remnant with twice the mass of the Sun compressed down into a tiny ball about 20 km across. All that angular momentum of the star is retained, and so the neutron star spins at an enormous speed.

The fastest neutron star ever recorded spins around 700 times a second. We know it’s turning this quickly because it’s blasting out beams of radiation that sweep towards us like an insane lighthouse. This, of course, is a pulsar, and we did a whole episode on them.

A regular star would be torn apart, but neutron stars have such intense gravity, they can rotate this quickly. Over time, the radiation streaming from the neutron star strips away its angular momentum, and it slows down.

A black hole with an accretion disk. Credit: (NASA/Dana Berry/SkyWorks Digital)

Black holes can spin even faster than that. In fact, when a black hole is actively feeding from a binary companion, or a supermassive black hole is gobbling up stars, it can rotate at nearly the speed of light. The laws of physics prevent anything in the Universe spinning faster than the speed of light, and black holes go right up to the edge of the law without breaking it.

Astronomers recently found a supermassive black hole spinning up to 87% the maximum speed permitted by relativity.

If you were hoping there are antimatter lurking out there, hoarding all that precious future energy, I’m sorry to say, but astronomers have looked and they haven’t found it. Just like the socks in your dryer, we may never discover where it all went.

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Categories: space

New Dwarf Planet Discovered Beyond Neptune

Universe Today - 11 July, 2016 - 21:41

A new dwarf planet has been discovered beyond Neptune, in the disk of small icy worlds that resides there. The planet was discovered by an international team of astronomers as part of the Outer Solar Systems Origins Survey (OSSOS). The instrument that found it was the Canada-France Hawaii Telescope at Maunakea, Hawaii. The planet is about 700 km in size, and has been given the name 2015 RR245. It was first sighted by Dr. JJ Kavelaars, of the National Research Council of Canada, in images taken in 2015. Dwarf planets are notoriously difficult to spot, but they're important pieces of the puzzle in tracing the evolution of our Solar System. Dr. Michele Bannister, of the University of Victoria in British Columbia, describes the moment when the planet was discovered: "There it was on the screen— this dot of light moving so slowly that it had to be at least twice as far as Neptune from the Sun.” "The icy worlds beyond Neptune trace how the giant planets formed and then moved out from the Sun. They let us piece together the history of our Solar System. But almost all of these icy worlds are painfully small and faint: it's really exciting to find one that's large and bright enough that we can study it in detail." said Bannister. As the New Horizons mission has shown us, these far-flung, cold bodies can have exotic features in their geological landscapes. Where once Pluto, king of the dwarf planets, was thought to be a frozen body locked in time, New Horizons revealed it to be a much more dynamic place. The same may be true of RR245, but for now, not much is known about it. The 700 km size number is really just a guess at this point. More measurements will need to be taken of its surface properties to verify its size. "It's either small and shiny, or large and dull." said Bannister. As our Solar System evolved, most dwarf planets like RR245 were destroyed in collisions, or else flung out into deep space by gravitational interactions as the gas giants migrated to their current positions. RR245 is one of the few that have survived. It now spends its time the same way other dwarf planets like Pluto and Eris do, among the tens of thousands of small bodies that orbit the sun beyond Neptune. RR245 has not been observed for long, so much of what's known about its orbit will be refined by further observation. But at this point it appears to have a 700 year orbit around the Sun. And it looks like for at least the last 100 million years it has travelled its current, highly elliptical orbit. For hundreds of years, it has been further than 12 billion km (80 AU)from the Sun, but by 2096 it should come within 5 billion km (34 AU) of the Sun. The discovery of RR 245 came as a bit of a surprise to the OSSOS team, as that's not their primary role. "OSSOS was designed to map the orbital structure of the outer Solar System to decipher its history," said Prof. Brett Gladman of the University of British Columbia in Vancouver. "While not designed to efficiently detect dwarf planets, we're delighted to have found one on such an interesting orbit". OSSOS has discovered over 500 hundred trans-Neptunian objects, but this is the first dwarf planet it's found. "OSSOS is only possible due to the exceptional observing capabilities of the Canada-France-Hawaii Telescope. CFHT is located at one of the best optical observing locations on Earth, is equipped with an enormous wide-field imager, and can quickly adapt its observing each night to new discoveries we make. This facility is truly world leading." said Gladman. A lot of work has been done to find dwarf planets in the far reaches of our Solar System. It may be that RR 245 is the last one we find. If there are any more out there, they may have to wait until larger and more powerful telescopes become available. In the mid-2020's, the Large Synoptic Survey Telescope (LSST) will come on-line in Chile. That 'scope features a 3200 megapixel camera, and each image it captures will be the size of 40 full Moons. It'll be hard for any remaining dwarf planets to hide from that kind of imaging power. As for RR 245's rather uninspiring name, it will have to do for a while. But as the discoverers of the new dwarf planet, the OSSOS team will get to submit their preferred name for the planet. After that, it's up the International Astronomical Union (IAU) to settle on one. What do you think? If this is indeed the last dwarf planet to be found in our Solar System what should we call it?

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Categories: space

Messier 18 (M18) – The NGC 6613 Star Cluster

Universe Today - 11 July, 2016 - 19:00

Welcome back to Messier Monday! In our ongoing tribute to the great Tammy Plotner, we take a look at the Messier 18 open star cluster. Enjoy! In the 18th century, while searching the night sky for comets, French astronomer Charles Messier began noticing a series of “nebulous objects” in the night sky. Hoping to ensure that other astronomers did not make the same mistake, he began compiling a list of these objects,. Known to posterity as the Messier Catalog, this list has come to be one of the most important milestones in the research of Deep Sky objects. One of these objects was Messier 18 (aka. NGC 6613), a relatively dim open star cluster located in the constellation Sagittarius. Located in close proximity to Messier 17 (the Omega Nebula), it is possible that these two clusters formed together. Description: Located about 4,900 light years from Earth, and spread over an expanse measuring 17 light-years across, this group of around 20 stars is only about 32 million years old. Its hottest members are spectral type B3, yet you will also see many yellow and orange stars as well. But as already noted, M18 may not be alone in space. According to research done by R. and C. R. de la Fuente Marcos, M18 may very well be a binary cluster, paired with the open cluster - NGC 6618 - which is harbored inside M17: "We have shown that binary open clusters appear to constitute a statistically significant sample and that the fraction of possible binary clusters in the Galactic disk is comparable to that in the Magellanic Clouds. The spatial proximity of two almost coeval open clusters, compared to the large distances which typically separate these objects, suggests that both objects were formed together. In starforming complexes, one star cluster might capture another to form a bound state in the presence of a third body or of energy dissipation. This mechanism may also be at work within orbital resonances for non-coeval clusters." History of Observation: M18 was one of Charles Messier's original discoveries, which took place in 1764. As he wrote in his notes upon observing the cluster: "In the same night [June 3 to 4, 1764], I have discovered a bit below the nebula reported here above, a cluster of small stars, environed in a thin nebulosity; its extension may be 5 minutes of arc: its appearances are less sensible in an ordinary refractor of 3 feet and a half [FL] than that of the two preceding [M16 and M17]: with a modest refractor, this star cluster appears in the form of a nebula; but when employing a good instrument, as I have done, one sees well many of the small stars: after my observations I have determined its position: its right ascension is 271d 34' 3", and its declination 17d 13' 14" south." In this circumstance, we must give Messier great credit considering his observations were performd long before the nature of open clusters and stellar movement were understood. While Messier seems to have spotted some nebulosity around the cluster (which may have belonged to M17), he takes a later historic cut from Smyth: "A neat double star, in a long and straggling assemblage of stars,below the Polish shield. A 9 and B 11 [mag], both blueish. This cluster was discovered by Messier in 1764, and registered as a mass of small stars appearing like a nebula in a 3 1/2-foot telescope; which affords another instance that the means of that very zealous observer did not quadrate with his diligence." What a shame Smyth wasn't around to later know that M18 could be paired with its nebulous neighbor! Locating Messier 18: Because Messier 18 is nothing more than a small collection of stars which are slightly brighter than the background Milky Way stars, it isn't easy to distinguish it using binoculars or a finderscope if you've never seen it before. One of the most sure ways of locating it is to become familiar with Messier 17 and simply aim a couple of degrees (about a field of view) south. While it won't strike you as a grand object, you will notice that the stars are compressed in this area and that there are several dozen of them which appear brighter than the rest. In a telescope, use your lowest magnification. Since this is a very well spread cluster, it is easily resolved in even modest instruments. And here are the quick facts on M18 to get you started: Object Name: Messier 18 Alternative Designations: M18, NGC 6613 Object Type: Open Star Cluster Constellation: Sagittarius Right Ascension: 18 : 19.9 (h:m) Declination: -17 : 08 (deg:m) Distance: 4.9 (kly) Visual Brightness: 7.5 (mag) Apparent Dimension: 9.0 (arc min) We have written many interesting articles about Messier Objects here at Universe Today. Here’s Tammy Plotner’s Introduction to the Messier Objects, , M1 – The Crab Nebula, M8 – The Lagoon Nebula, and David Dickison’s articles on the 2013 and 2014 Messier Marathons. Be to sure to check out our complete Messier Catalog. And for more information, check out the SEDS Messier Database.

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Categories: space

A Planet With A 27,000 Year Orbit & That’s Just Where The Strangeness Begins

Universe Today - 11 July, 2016 - 18:28

Every planet in the Solar System has its own peculiar orbit, and these vary considerably. Whereas planet Earth takes 365.25 days to complete a single orbit about our Sun, Mars takes almost twice as long - 686.971 days. Then you have Jupiter and the other gas giants, which take between 11.86 and 164.8 years to orbit our Sun. But even with these serving as examples, astronomers were not prepared for what they found when they looked at CVSO 30. This star system, which lies some 1200 light years from Earth, has been found in recent years to have two candidate exoplanets. These planets, which are many times the mass of Jupiter, were discovered by an international team of astronomers using both the Transit Method and Direct Imaging. And what they found was very interesting: one planet has an orbital period of less than 11 days while the other takes a whopping 27,000 years to orbit its parent star! In addition to being a big surprise, the detection of these two planets using different methods was an historic achievement. Up until now, the vast majority of the over 2,000 exoplanets discovered have been detected thanks to indirect methods. These include the aforementioned Transit Method, which detects planets by measuring the dimming effect they cause when crossing their parent star's path, and the Radial Velocity Method, which measures the gravitational effect planets have on their parent star. In 2012, astronomers used the Transit Method to detect CVSO 30b, a planet with 5 to 6 times the mass of Jupiter, and which orbits its star at a distance of only 1.2 million kilometers (by comparison, Mercury orbits our Sun at a distance of 58 million kilometers). From these characteristics, CVSO 30b can be described as a particularly "hot-Jupiter". In contrast, Direct Imaging has been used to spot only a few dozen exoplanets. The reason for this is because it is typically quite difficult to detect the light reflected by a planet's atmosphere due it being drowned out by the light of its parent star. It can also quite demanding when it comes to the instrument involved. Still, compared to indirect methods, it can be more effective when it comes to exploring the remote regions of a star. Thanks to the efforts of an international team of astronomers, who combined the of the Keck Observatory in Hawaii, the ESO's Very Large Telescope in Chile, and the Spanish National Research Council's (CSIC) Calar Alto Observatory, CVSO 30c was spotted in remote regions around its parent star, orbiting at a distance of around 666 AU. The details of the discovery were published in a paper titled "Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30". In it, the researchers - who hail from such prestigious institutions as the Cerro Tololo Inter-American Observatory, the Jena Observatory, the European Space Agency and the Max Planck Institute for Astronomy - explained the methods used to find the exoplanet, and the significance of its discovery. As Tobias Schmidt - of the University of Hamburg, the Astrophysical Institute and University Observatory Jena, and the lead author of the paper - told Universe Today via email: "[30b and 30c] are both unusual on their own. CVSO 30b is the first transiting planet around a star as young as 2.5 million years. Published in 2012, all previously detected transiting planets were older than few hundred million years... It has been a surprise to find a planetary mass companion at 662 AU, or 662 times the distance from Earth to the Sun, from a primary star having only about 0.4 solar masses. According to the standard model, planets form in disks around the star. But none of the observed disks around such low-mass stars is large enough to form such an object." In other words, it is surprising to find two exoplanet candidates with several times the mass of Jupiter (aka. Super-Jupiters) orbiting a star as small as CVSO 30. But to find that two exoplanets with such a disparity in terms of their respective distance from their star (despite being similar in mass) was particularly surprising. Relying on high-contrast photometric and spectroscopic observations from the Very Large Telescope, the Keck telescopes, and the Calar Alto observatory, the international team was able to spot 30c using a technique known as lucky imaging. This process, which is used by ground-based telescopes, involves many high-speed, quick exposure photos being taken to minimize atmospheric interference. What they found was an exoplanet with a wide orbit that was between 4 and 5 Jupiter masses, and was also very young - less than 10 million years old. What's more, the spectroscopic data indicated that it is unusually blue for a planet, as most other planet candidates of its kind are very red. The researchers concluded from this that it is likely that 30c is the first young planet of its kind to be directly imaged. They further concluded that 30 c is also likely the first "L-T transition object" younger than 10 million years to be found orbiting a star. L-T transition objects are a type of brown dwarf - objects that are too large to be considered planets, but too small to be considered stars. Typically they are found embedded in large clouds of gas and dust, or on their own in space. Paired with its companion - 30 b, which is impossibly close to its parent star - 30 c is not believed to have formed at its current position, and is likely not stable in the long-term. At least, not where current models of planetary formation and orbit are concerned. However, as Prof. Schmidt indicated, this offers a potential explanation for the odd nature of these exoplanets. "We do think this is a very good hint," he said, "that the two objects might have formed regularly around the star at a separation comparable to Jupiter or Saturn's separation from the Sun, then interacted gravitationally and were scattered to their current orbits. However this is still speculation, further investigations will try to prove this. Both have about the same mass of few Jupiter masses, the inner one might be even lower." The discovery is also significant since it was the first time that these two detection methods - Transit and Direct Imaging - were used to confirm exoplanet candidates around the same star. In this case, the methods were quite complimentary, and present opportunities to learn more about exoplanets. As Professor Schmidt explained: "Both Transit method and radial velocity method have problems finding planets around young stars, as the activity of young stars is disturbing the search for them. CVSO 30 b was the first very young planet found with these methods, currently a hand full of candidates exist. Direct imaging, on the other hand, is working best for young planets as they still contract and are thus self-luminous. It is therefore great luck that a far out planet was found around the very first young star hosting a inner planet... "However, the real advantage of transit and direct imaging methods is that the two objects can now be investigated in greater detail. While we can use the direct light from the imaging for spectroscopy, i.e. split the light according to its wavelength, we hope to achieve the same for the inner planet candidate. This is possible as the light passes through the atmosphere of the planet during transits and some of the elements are absorbed by the composition material of the atmosphere. So we do hope to learn a lot about planet formation, thus also formation of the early Solar System and about young planets in particular from the CVSO 30 system." Since astronomers first began began to find exoplanet candidates in distant star systems, we have come to learn just how diverse our Universe really is. Many of the discoveries have challenged our notions about where planets can form around their parent star, while others have showed us that planets can take many different forms. As time goes on and our exploration of the local Universe advances, we will be challenged to find explanations for how it all fits together. And from that, new and more comprehensive models will no doubt emerge. Further Reading: IAA, arXiv

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Categories: space

Flawless Shakedown Mission from Modified Soyuz Delivers Multinational Crew to Space Station

Universe Today - 10 July, 2016 - 04:06

A flawless shakedown mission from Russia’s newly modified Soyuz capsule successfully delivered a new multinational crew to the Space Station early Saturday, July 9 after a two day orbital chase. The upgraded Soyuz MS-01 spacecraft launching on its maiden flight successfully docked to the International Space Station at 12:06 a.m. EDT Saturday, July 9, while soaring 254 statute miles over the South Pacific. “Docking confirmed,” said a commentator from Russian mission control at Korolev outside Moscow. “Contact and capture complete.” The Soyuz was ferrying the new multinational trio of astronauts and cosmonauts comprising Kate Rubins of NASA, Soyuz Commander Anatoly Ivanishin of the Russian space agency Roscosmos and Takuya Onishi of the Japan Aerospace Exploration Agency on the Expedition 48/49 mission. The three person crew of two men and one woman had launched flawlessly into picture perfect skies two days earlier from the Baikonur Cosmodrome in Kazakhstan at 9:36 p.m. EDT Wednesday, July 6 (7:36 a.m. Baikonur time, July 7), in the brand new version of the Russian Soyuz capsule that has been significantly upgraded and modified. NASA’s Kate Rubins was strapped into the right seat, Ivanishin in the center and Onishi on the left. It was a textbook approach on the shakedown mission that culminated in a flawless docking at the Earth-facing Russian Rassvet module on the Russian side of the massive orbiting outpost. NASA TV carried the whole operation live with beautiful color video imagery streaming from the ISS showing the Soyuz approach and black and white video streaming from the Soyuz. The Soyuz performed magnificently. All of the upgraded and modified systems checked out perfectly on this maiden flight of the new version of Russias venerable Soyuz, said NASA commentator Rob Navias. “All new systems functioning perfectly,” said Navias. "This has been a perfect shakedown mission for the new Soyuz crew docking at the ISS.” The Soyuz had slowed to an approach velocity of just 0.1 m/s at docking with the forward docking probe extended. The approach was fully automated under Russian mission control as Ivanishin carefully monitored all spacecraft systems with steady update calls back to ground control. The fully automated approached utilized the upgraded KURS NA automated rendezvous radar system. During final approach, the Soyuz conducted a fly around maneuver starting at a distance of 400 meters. It moved 57 degress around the station while closing in to about 250 meters. After station keeping for about 2 minutes while ground controllers conducted a final evaluation and no issues were detected, Russian mission control at last gave the GO for final approach and the GO command for docking was given. The Soyuz made contact and completed a perfect docking at Rassvet. The hook and latches were then closed in for a tight grasp onto the station. The crews then conducted a series of leak and pressurization checks. After everything checked out, the hatches were finally opened about two and a half hours later at 2:26 a.m. EDT. The new crew members of Expedition 48 officially floated aboard the International Space Station at about 2:50 a.m. EDT, July 9 with the hatches opened between their Soyuz MS-01 and the space station and after a live video transmission link had been established to show the festivities. They were welcomed aboard with hugs and joined the Expedition 48 Commander Jeff Williams of NASA and Flight Engineers Oleg Skripochka and Alexey Ovchinin of Roscosmos. With the arrival of Rubins, Ivanishin and Onishi, the stations resident crew is beefed up to its normal six person crew complement. They soon held the traditional video telecon for well wishes and congratulations from family, friends and mission officials. The new trio will spend at least four months at the orbiting lab complex conducting more than 250 science investigations in fields such as biology, Earth science, human research, physical sciences, and technology development. Rubins is on her rookie space mission. She holds a bachelor’s degree in molecular biology and a doctorate in cancer biology which will be a big focus of her space station research activities. The new trio will join Expedition 48 Commander Jeff Williams of NASA and Flight Engineers Oleg Skripochka and Alexey Ovchinin of Roscosmos. “The approximately 250 research investigations and technology demonstrations - not possible on Earth - will advance scientific knowledge of Earth, space, physical, and biological sciences. Science conducted on the space station continues to yield benefits for humanity and will enable future long-duration human and robotic exploration into deep space, including the agency’s Journey to Mars,” says NASA. The newly upgraded Soyuz offers increased reliability and enhanced performance. Many changes were instituted including enhanced structural performance to minimize chances of micrometeoroid penetration. Engineers also added a fifth battery for more power and storage capacity. The solar arrays are also about one square meter larger and the efficiency of the solar cells increased about 2 percent. Also a more modern command and telemetry system to interact with a new series of new Russian communications satellites that will offer greatly increased the coverage by ground control. This was previously only about 20 minutes per orbit while over Russian ground stations and will now increase up to 45 to 90% of orbital coverage via the Russian comsat system. A phased array antenna was also added with increased UHF radio capability in the Soyuz descent module that now also include a GPS system to improve search and rescue possibilities. The newly upgraded KURS rendezvous radar system will weigh less, use less power and overall will be less complicated. For example it doesn’t have to be moved out of the way before docking. Weighs less and uses less power. New approach and attitude control thrusters were installed. The new configuration uses 28 thrusters with a redundant thruster for each one - thus two fully redundant manifolds of 28 thrusters each. All of these modification were tested out on the last two progress vehicles. Multiple unmanned cargo ships carrying tons of essential supplies and science experiments are also scheduled to arrive from Russia, the US and Japan over the next few months. A SpaceX Dragon is scheduled to launch as soon as July 18 and an Orbital ATK Cygnus should follow in August. The SpaceX Dragon CRS-9 mission is slated to deliver the station’s first International docking adapter (IDA) to accommodate the future arrival of U.S. commercial crew spacecraft, including the Boeing built Starliner and SpaceX built Crew Dragon. A Japanese HTV cargo craft will carry lithium ion batteries to replace the nickel-hydrogen batteries currently used on station to store electrical energy generated by the station’s huge rotating solar arrays. Two Russian Progress craft with many tons of supplies are also scheduled to arrive. Stay tuned here for Ken's continuing Earth and Planetary science and human spaceflight news. Ken Kremer

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Categories: space

A ‘Cosmic Miracle’: Indications Of Early Forming ‘Direct Collapse’ Black Hole Seen

Universe Today - 8 July, 2016 - 21:18

Astronomers have been finding some extremely old supermassive black holes, ones that formed when the Universe was quite young. But they were puzzled at how a black hole could grow to such tremendous size when the Universe itself was just a toddler. Astronomers have now found a unique set of conditions were present half a billion years after the Big Bang that allowed these monster black holes to form. An unusual source of intense radiation created what are called "direct-collapse black holes.” "It's a cosmic miracle," said Volker Bromm of The University of Texas at Austin, who worked with several astronomers on the finding. "It's the only time in the history of the universe when conditions are just right for them to form.” The conventional understanding of how black holes form is called the accretion theory, where an extremely massive star collapses and black hole “seeds” are built from the collapse by pulling in gas from their surroundings and by mergers of smaller black holes. But that process takes a long time, much longer than the time these quickly forming black holes were around. Plus, the early universe didn’t have the quantities of gas and dust needed for supermassive black holes to grow to their gigantic size. The new findings suggest instead that some of the first black holes formed directly when a cloud of gas collapsed, bypassing any other intermediate phases, such as the formation and subsequent destruction of a massive star. Of course, like any black hole, these “direct collapse” black holes can’t be seen. But there was strong evidence for their existence, as they are needed to power the highly luminous quasars detected in the young universe. A quasar's great brightness comes from matter spiraling into a supermassive black hole, heating to millions of degrees, creating jets that shine like beacons across the Universe. But since the accretion theory doesn’t explain supermassive black holes in extremely distant — and therefore young — universe, astronomers couldn’t explain the quasars either. This has been called "the quasar seed problem." "The quasars observed in the early universe resemble giant babies in a delivery room full of normal infants,” said Avi Loeb from the Harvard-Smithsonian Center for Astrophysics, who worked with Bromm. “One is left wondering: what is special about the environment that nurtured these giant babies? Typically the cold gas reservoir in nearby galaxies like the Milky Way is consumed mostly by star formation." But In 2003, Bromm and Loeb came up with a theoretical idea to get an early galaxy to form a supermassive seed black hole, by suppressing the otherwise prohibitive energy input from star formation. They called the process "direct collapse." “Begin with a "primordial cloud of hydrogen and helium, suffused in a sea of ultraviolet radiation," Bromm said. “You crunch this cloud in the gravitational field of a dark-matter halo. Normally, the cloud would be able to cool, and fragment to form stars. However, the ultraviolet photons keep the gas hot, thus suppressing any star formation. These are the desired, near-miraculous conditions: collapse without fragmentation! As the gas gets more and more compact, eventually you have the conditions for a massive black hole." This set of cosmic conditions appears to have only existed in the very early universe, and this process does not happen in galaxies today. To test their theory, Bromm, Loeb and their colleague Aaron Smith started studying a galaxy called CR7, identified by a Hubble Space Telescope survey called COSMOS as being around at less than 1 billion years after the Big Bang. David Sobral of the University of Lisbon had made follow-up observations of CR7 with some of the world's largest ground-based telescopes, including Keck and the VLT. These uncovered some extremely unusual features in the light signature coming from CR7. Specifically, the Lyman-alpha hydrogen line was several times brighter than expected. Remarkably, the spectrum also showed an unusually bright helium line. "Whatever is driving this source is very hot — hot enough to ionize helium," Smith said, about 100,000 degrees Celsius. These and other unusual features in the spectrum meant that it could either be a cluster of primordial stars or a supermassive black hole likely formed by direct collapse. Smith ran simulations for both scenarios and while the star cluster scenario "spectacularly failed," Smith said, the direct collapse black hole model performed well. Also, earlier this year, researchers using combined data from the Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space Telescope to identify these possible black hole seeds. They found two objects, both of these matched the theoretical profile in the infrared data. (read their paper here.) It seems astronomers are "converging on this model," Smith said, for solving the quasar seed problem and the early black hole conundrum. Stay tuned. Bromm, Loeb and Smith's work is published in the journal Monthly Notices of the Royal Astronomical Society. Sources: RAS, Harvard-Smithsonian CfA, Press release for NASA's detection of direct collapse black holes earlier this year.

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Categories: space

What if Earth Stopped Orbiting the Sun?

Universe Today - 8 July, 2016 - 19:32

In a previous article I investigated what would happen if the Earth stopped turning entirely, either locking to the Sun or the background stars.

If it happened quickly, then results would be catastrophic, turning the whole planet into a blended slurry of mountains, oceans and trees, hurting past a hundreds of kilometers per hour. And if it happened slowly, it would still be unpleasant, as we stopped having a proper day/night cycle. But it wouldn’t be immediately lethal.

But would happen if the Earth somehow just stopped in its tracks as it was orbiting the Sun, as if it ran into an invisible wall? As with the Earth turning question, it’s completely and totally impossible; it’s not going to happen. And with the unspun Earth, it would be totally devastating and super interesting to imagine.

Credit: Xinhua News, via

Before we begin to imagine the horrifying consequences of a total loss of orbital velocity, let’s examine the physics involved.

The Earth is traveling around the Sun with an orbital velocity of 30 kilometers per second. This is exactly the speed it needs to be going to counteract the force of gravity from the Sun pulling it inward. If the Sun were to suddenly disappear, Earth would travel in a perfectly straight line at 30 km/s. This is how orbits work.

If the Earth’s orbital velocity sped up, then it would go into a higher orbit to compensate. And if the Earth’s orbital velocity slowed down, then it fall into a lower orbit to compensate. And if the Earth’s orbital velocity was slowed all the way down to zero? Now we’re cooking, literally.

First, let’s imagine what would happen if the Earth just suddenly stopped.

As I mentioned above, the Earth’s orbital velocity is 30 km/s, which means that if it suddenly stopped, everything on it would still have 30 km/s worth of inertia. The escape velocity of the Earth is about 11 km/s.

In other words, anything on the Earth’s leading side would fly off into space, continuing along the Earth’s orbital path around the Sun. Anything on the trailing side would be pulverized against the Earth. It would be a horrible, gooey mess.

But even if the Earth slowed gently to a stop, it would still be a horrible mess. Without the outward centripetal force to counteract the inward pull of gravity, the Earth would begin falling towards the Sun.

How long would it take? My integral calculus is a little rusty, so I’ll draw upon the calculations of Dave Rothstein from Cornell’s Ask an Astronomer. According to Dr. Rothstein, the whole journey would take about 65 days. It would take 41 days to cross the orbit of Venus, and on day 57, we’d cross the orbit of Mercury.

As they days went by, the Earth would get hotter and hotter as it got closer to the Sun. Aatish Bhatia over at WIRED did some further calculations to figure out the temperature. A month into the freefall, and the average temperature on Earth would have risen to 50 degrees C. 50 days in and we’d be about 125 C. On the final day, we’d get up to 3,000 C… and then, that would be that.

Of course, this is completely and totally impossible. There’s no force that could just stop the Earth in its tracks like that. There is, however, a plausible scenario that might drag the Earth into the Sun.

In the far future, the Sun will turn into a red giant and expand outward, engulfing the orbits of Mercury and Venus. There’s still an argument among astronomers on whether it’s going to gobble up Earth as well.

Poor Earth. © Digital Drew.

Let’s say it does. In that case, the Earth will be inside the atmosphere of the Sun, and experience a friction from the solar material as it orbits around, and spiral inward. Of course, at this point you’re orbiting inside the Sun, so falling into the Sun already happened.

There you go. If the Earth happened to stop dead in its orbit, it would take about 65 days to plunge down into the Sun, disappearing in a puff of plasma.

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Categories: space

Astronomers Discover Exoplanet With Triple Sunrises and Sunsets

Universe Today - 8 July, 2016 - 15:10

In the famous scene from the Star Wars movie "A New Hope" we recall young Luke Skywalker contemplating his future in the light of a binary sunset on the planet Tatooine. Not so many years later in 2011, astronomers using the Kepler Space Telescope discovered Kepler-16b, the first Tatooine-like planet known to orbit two suns in a binary system. Now astronomers have found a planet in a triple star system where an observer would either experience constant daylight or enjoy triple sunrises and sunsets each day, depending on the seasons, which last longer than human lifetimes.

They used the SPHERE instrument on the European Southern Observatory’s Very Large Telescope to directly image the planet, the first ever found inside a triple-star system. The three stars are named HD 131399A, HD 131399B and HD 131399C in order of decreasing brightness; the planet orbits the brightest and goes by the chunky moniker HD 131399Ab.

Located about 320 light-years from Earth in the constellation of Centaurus the Centaur HD 131399Ab is about 16 million years old, making it also one of the youngest exoplanets discovered to date, and one for which we have a direct image. With a temperature of around 1,075° F (580° C) and the mass about four times that of Jupiter, it's also one of the coldest and least massive directly-imaged exoplanets.

To pry it loose from the glare of its host suns, a team of astronomers led by the University of Arizona used a state of the art adaptive optics system to give razor-sharp images coupled with SPHERE, an instrument that blocks the light from the central star(s) similar to the way a coronagraph blocks the brilliant solar disk and allows study of the Sun's corona. Finally, the region around the star is photographed in infrared polarized light to make any putative planets stand out more clearly against the remaining glare. The planet, HD 131399Ab, is unlike any other known world — its orbit around the brightest of the three stars is by far the widest known within a multi-star system. It was once thought that planets orbiting a multi-star system would be unstable because of the changing gravitational tugs on the planet from the other two stars. Yet this planet remains in orbit instead of getting booted out of the system, leading astronomers to think that planets orbiting multiple stars might be more common that previously thought. HD 131399Ab orbits HD 131399A, estimated to be 80% more massive than the Sun. Its double-star companions orbit about 300 times the Earth-Sun distance away. For much of the planet’s 550 year orbit, all three stars would appear close together in the sky and set one after the other in unique triple sunsets and sunrises each day. But when the planet reached the other side of its orbit around its host sun, that star and the pair would lie in opposite parts of the sky. As the pair set, the host would rise, bathing HD 131399Ab in near-constant daytime for about one-quarter of its orbit, or roughly 140 Earth-years. Click to see a wonderful simulation showing how the planet orbits within the trinary system Planets in multi-star systems are of special interest to astronomers and planetary scientists because they provide an example of how the mechanism of planetary formation functions in these more extreme scenarios. Since multi-star systems are just as common as single stars, so planets may be too. How would our perspective of the cosmos change I wonder if Earth orbited triple suns instead of a single star? Would the sight deepen our desire for adventure like the fictional Skywalker? Or would we suffer the unlucky accident of being born at the start of a multi-decade long stretch of constant daylight? Wonderful musings for the next clear night under the stars.

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Categories: space

Now, Witness The Power Of This Fully Operational Radio Telescope!

Universe Today - 8 July, 2016 - 01:12

Relax, its not a space station! And according to the Chinese government, it's for entirely peaceful purposes. It's known as the Five-hundred-meter Aperture Spherical Telescope (FAST), a massive array that just finished construction in the southerwestern province of Guizhou, China. Equivalent in size to over 20 football fields joined end to end, it is the world's largest radio telescope - thus ending the Arecibo Observatory's 53 year reign. As part of China's growing commitment to space exploration, the FAST telescope will spend the coming decades exploring space and assisting in the hunt for extraterrestrial life. And once it commences operations this coming September, the Chinese expect it will remain the global leader in radio astronomy for the next ten or twenty years. In addition to being larger than the Arecibo Observatory (which measures 305 meters in diameter), the telescope is reportedly 10 times more sensitive than its closest competitor - the steerable 100-meter telescope near Bonn, Germany. What's more, unlike Arecibo (which has a fixed spherical curvature), FAST is capable of forming a parabolic mirror. That will allow researchers a greater degree of flexibility. The Chinese Academy of Sciences (CAS) has spent the past five years building the telesccope, to the tune of 1.2-billion-yuan (180 million U.S. dollars). As the deputy head of the National Astronomical Observation, which is overseen by the CAS, Zheng Xiaonian was present at the celebrations marking the completion of the massive telescope. As he was paraphrased as saying by the Xinhua News Agency: "The project has the potential to search for more strange objects to better understand the origin of the universe and boost the global hunt for extraterrestrial life." Zheng was also quoted as saying that he expects FAST to be the global leader in radio astronomy for the next 10 to 20 years. The construction of this array has also been a source of controversy. To protect the telescope from radio interference, Chinese authorities built FAST in Guizhou province's isolated Dawodang depression, directly into the mountainside. However, to ensure that no magnetic disruptions are nearby, roughly 9,000 people are being removed from their homes and rehoused in the neighboring counties of Pingtang and Luodian. Li Yuecheng is the secretary-general of the Guizhou Provincial Committee, which is part of the Chinese People's Political Consultative Conference (CPPCC). As he was quoted as saying by the Xinhua News Agency, the move comes with compensation: "The proposal asked the government to relocate residents within 5 kilometers of the Five-hundred-meter Aperture Spherical Telescope, or FAST, to create a sound electromagnetic wave environment... Each of the involved residents will get 12,000 yuan (1,838 U.S. dollars) subsidy from the provincial reservoir and eco-migration bureau, and each involved ethnic minority household with housing difficulties will get 10,000 yuan subsidy from the provincial ethnic and religious committee." In addition, the construction of this telescope is seen by some as part of a growing desire on behalf of China to press its interests in the geopolitical realm. For instance, in their 2016 Annual Report to Congress, the Department of Defense indicated that China is looking to develop its space capabilities to prevent adversaries from being able to use space-based assets in a crisis. As the report states: "In parallel with its space program, China continues to develop a variety of counterspace capabilities designed to limit or to prevent the use of space-based assets by the [Peoples' Liberation Army’s] adversaries during a crisis or conflict... Although China continues to advocate the peaceful use of outer space, the report also noted China would 'secure its space assets to serve its national economic and social development, and maintain outer space security.'" However, for others, FAST is merely the latest step in China's effort to become a superpower in the all-important domain of space exploration and research. Their other ambitions include mounting a crewed mission to the Moon by 2036 and building a space station (for which work has already begun). In addition, FAST will enable China to take part in another major area of space research, which is the search for extra-terrestrial life. For decades, countries like the United States have leading this search through efforts like the SETI Institute and the Nexus for Exoplanet System Science (NExSS). But with the completion of this array, China now has the opportunity to make significant contributions in the hunt for alien intelligence. In the meantime, the CAS' scientists will be debugging the telescope and conducting trials in preparation for its activation, come September. Once it is operational, it will assist in other areas of research as well, which will include conducting surveys of neutral hydrogen in the Milky Way and other galaxies, as well as detecting pulsars and gravitational waves. Further Reading: Xinhuanet

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Categories: space

Jovians Distressed At Strange, Tiny & Silent Creatures Aboard Spacecraft

Universe Today - 7 July, 2016 - 20:50

Given its historic importance - being just the second spacecraft to conduct a long-term mission to Jupiter - NASA was sure to outfit the Juno probe with some high-end memorabilia. These include the Galileo commemorative plaque*, which shows Galileo's face and the words he wrote when he first observed Jupiter’s four largest moons in 1610 (known today as the Galilean Moons). In addition, three commemorative figures (each measuring 4 cm high) were created especially for the mission. Created by Lego, these figurines depict the Roman god Jupiter, his wife Juno, and the astronomer Galileo Galilei - each holding an identifying object. Constructed from aluminum so they could withstand the trip and the radiation of the gas giant, these figures arrived with the probe around Jupiter on Monday, July 4th. Much like the Juno spacecraft that is ferrying them, these figurines have spent the past 5 years in space and traversing the 869 million kilometers that lie between Earth from Jupiter. As part of Lego's "Build Your Future" campaign,  the trio are part of an educational outreach program to inspire kids around the world to learn about science and technology. A key part of this effort is the Building Challenge launched by Lego to raise awareness about space exploration. For this challenge, participants are asked to build their vision of the future of space exploration using Lego bricks, take pictures of their creation, and then upload them to the Lego website's "Mission to Space" gallery. The winning creations will be featured on and the Gallery homepage. In addition, Lego's website has new content that encourages children to learn more about the Solar System. As they state on the webpage: "Have you ever wondered what it would be like if you could visit other planets and travel through space? Well, here’s your chance to go on a mission to Space through a partnership between NASA and LEGO Group! Pack your space lunch, and get ready to fly the International Space Station, pass the Moon, to Mars and Jupiter! Learn fun facts about our solar system, play quizzes, and get a taste of life as an astronaut and space pioneer! Round off the trip by entering an out-of-this-world building challenge." True to their mythological roots, the figurine of Jupiter (the Roman equivalent of Zeus) is holding a lightning bolt. Juno, his wife, is holding a magnifying glass, which represents her ability to see through the clouds that Jupiter surrounded himself with. And Galileo, the famed astronomer who was the first to view Jupiter's moons, holds his famed telescope and an orb representing Jupiter. These three figurines are the closest thing the Juno spacecraft has to a crew. During the next two years, they will be with the probe as it orbits Jupiter a total of 37 times, conducting surveys of Jupiter's atmosphere, interior, magnetosphere, and gravitational field. When the mission is over, they will deorbit with the probe, crashing into Jupiter's atmosphere to prevent any contamination of Jupiter's moons. Over the course of the past three days, numerous memes have popped up across the internet, claiming that: "When Galileo first spotted Jupiter's largest moons, he named them after Jove's (Zeus') mistresses. Now, a probe named after his wife will arrive in the system, thus fulfilling a joke astronomers have been setting up for the past 400 years!" - I'm paraphrasing, of course! Nevertheless, the observation is an apt one. And to make this witty statement complete, all those figures who had a hand in lending Jupiter the cultural significant it has (be they historical or mythological) will be represented as Juno tries to unveil Jupiter's mysteries. Sure, those likenesses are just 4 cm in height, and they are built out of aluminum instead of marble, but it's the thought that counts! *The Galileo commemorative plague contains script written in Italian by Galileo's own hand. It reads: "On the 11th it was in this formation, and the star closest to Jupiter was half the size than the other and very close to the other so that during the previous nights all of the three observed stars looked of the same dimension and among them equally afar; so that it is evident that around Jupiter there are three moving stars invisible till this time to everyone.” And be sure to enjoy this video of NASA's Juno team celebrating the probe's arrival at Jupiter: Further Reading: NASA June, Lego

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