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  • richardmitnick 8:15 am on October 28, 2016 Permalink | Reply
    Tags: , , , Solar system   

    From Astronomy: “The outer solar system keeps getting weirder’ 

    Astronomy magazine

    astronomy.com

    October 27, 2016
    Nola Taylor Redd

    q
    WikiMedia Commons

    Several newly discovered objects on the outskirts of the solar system suggest that something strange is afoot. While some scientists point to the odd behavior of the newfound residents as further proof for the existence of the hypothetical Planet Nine (a yet-unseen superEarth proposed to inhabit the outskirts) not everyone is convinced.

    The new inhabitants include a small icy world with one of the longest known orbits and several smaller objects clustered together extremely far from the sun.

    The newest of these objects is L91, an icy world that can travel as far from the sun as 1430 astronomical units (AU), or 1,430 times the Earth-sun distance, one of the longest known orbital periods. L91 never draws closer to the sun than 50 AUs, farther away than even Pluto.

    And L91’s distant path is shifting.

    “It’s orbit is changing in quite a remarkable way,” astrophysicist Michele Bannister told scientists last week at the American Astronomical Society’s Division for Planetary Sciences in Pasadena, California. Bannister, an astrophysicist at Queen’s University Belfast, identified minute changes in the object’s orbit that could come from the passing gravity of other stars or interactions with the hypothetical Planet Nine. Simulations by the team suggest that the tiny tugs are more likely to come from beyond the solar system, whether distant stars or galactic winds.

    Konstantin Batygin, an astronomer at the California Institute of Technology, said, “I think it’s a story that’s not implausible, but I also think it’s not needed.” Batygin, who announced the existence of Planet Nine last January, thinks the unusual orbits of L91 and other newfound objects are more likely explained by the hypothetical planet.

    Bannister and her team spotted L91 using the Outer Solar System Origins Survey, a 4-year survey hunting distant moving objects using the Canada-France-Hawaii Telescope. L91’s mass and size remains unknown.

    “It’s right at the limit of what we could actually detect in the sky,” Bannister said.

    ‘Something is happening’

    L91 isn’t the only new object in the sky. Another team of astronomers reported a handful of smaller icy bodies traveling beyond Neptune. Similarities in the orbits of objects like these led to the proposal of Planet Nine.

    “A lot is going on in the outer solar system,” said Scott Sheppard of the Carnegie Institution for Science in Washington, D.C. Sheppard is part of a team of astronomers conducting the largest, deepest survey of trans-Neptunian objects, whose orbits take them farther out than Neptune. The team found several new objects clustered in the outer edges of the solar system.

    One of these objects, 2014 FE72, is the first known to come from the Oort Cloud, the icy shell around the solar system where comets are born.

    Oort Cloud NASA
    Oort Cloud NASA

    With an orbit that takes it out more than 3,000 AUs, it may also suffer from the influence of passing stars or the gravity of Planet Nine

    Sheppard and his colleagues have been mapping the sky in detail since 2007. So far, they’ve only covered about 10 percent of what he calls “the most interesting part of the sky.”

    But not all scientists are convinced that the increasing number of odd orbits points to Planet Nine.

    “We did search some parts of the sky more thoroughly than others,” says astronomer Katherine Volk, a planetary scientist at the University of Arizona. Volk analyzed the growing studies offered up as evidence for the hypothetical planet, and remains skeptical that it is the only conclusion. “You find things where you’re looking,” she says.

    She pointed out that the similarities in orbits, or clustering, of the objects could be related to their similar positions in the sky.

    “If the clustering persists at the end of [Sheppard’s] survey, it will be more convincing,” she said.

    At the same conference, Batygin reported that Planet 9 could be responsible for the backwards, or retrograde, orbit of some of the solar system’s centaurs. Orbiting among the outer planets, centaurs cross the orbits of their larger neighbors. And Elizabeth Bailey, a graduate student at Caltech working with Batygin, reported that Planet 9 could have tilted the orbit of the solar system’s planets with respect to the sun, solving another long-standing astronomical mystery.

    Again, Volk isn’t convinced that the research proves the existence of Planet Nine, though she said Batygin and Bailey’s had drawn reasonable conclusions.
    “There are all these different, slightly odd things,” she said. “No one piece of evidence is really convincing me that for sure there is a planet there, [but] the fact that there are multiple things probably says something is happening.”

    See the full article here .

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  • richardmitnick 2:51 pm on February 5, 2016 Permalink | Reply
    Tags: , , Solar system,   

    From Swinburne: “Adding a new dimension to the early chemistry of the Solar System” 

    Swinburne U bloc

    Swinburne University

    5 February 2016
    Contact
    Alyx Williams
    +61 3 9214 3760
    aewilliams@swin.edu.au

    Expert for comment
    Professor Sarah Maddison
    +61 03 9214 5971
    smaddison@swin.edu.au
    @ProfAstroSarah

    Solar system
    Solar System NASA/Chandra

    Using sophisticated computer simulations, an international research team have discovered new insights into the chemical composition of the dust grains that formed in the solar system 4.5 billion years ago.

    Researchers from Swinburne University of Technology, Melbourne and the University of Lyon, France, calculated a two-dimensional map of the dust chemistry in the solar nebula, the thin dusty disk that surrounded the young sun and out of which the planet formed.

    It is expected that refractories (high temperature materials) should be located close to the young sun, while volatile materials (such as ices and sulphur compounds) should form far from the sun where temperatures are cooler.

    However, the new maps produced by the research team revealed a complex chemical distribution of the dust, where refractory materials were also present at large distances from the sun on the surface of the disk. Volatile materials were also found in the inner disk close to the young sun.

    “The new two-dimensional calculations have given us a clearer idea of the pristine chemistry in our solar system soon after its formation,” says lead researcher Francesco Pignatale.

    “While solar nebular is thin, it is two-dimensional. This makes it possible to find relatively high temperature regions at larger distances from the sun on the surface of the disk that are heated by the sun’s rays.

    “We also find colder regions in the inner disk closer to the sun. Here the high concentration of dust prevents the stellar radiation from efficiently heating the local environment.”

    This research was conducted as part of Dr Pignatale’s PhD at Swinburne.

    The research team also included Swinburne Dean of Science, Professor Sarah Maddison, Dr Kurt Liffman and Professor Geoff Brooks.

    This research was published in the Monthly Notices of the Royal Astronomical Society.

    See the full article here .

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    Swinburne U Campus

    Swinburne is a large and culturally diverse organisation. A desire to innovate and bring about positive change motivates our students and staff. The result is in an institution that grows and evolves each year.

     
  • richardmitnick 10:32 am on August 18, 2015 Permalink | Reply
    Tags: , , Solar system   

    From Carnegie: “Solar System formation don’t mean a thing without that spin” 

    Carnegie Institution for Science
    Carnegie Institution for Science

    August 18, 2015
    Alan Boss

    New work from Carnegie’s Alan Boss and Sandra Keiser provides surprising new details about the trigger that may have started the earliest phases of planet formation in our solar system. It is published by The Astrophysical Journal.

    2
    These images show the central plane of a rotating disk orbiting a newly formed protostar (dark dot) formed in a three-dimensional model of the shock-triggered collapse of a molecular cloud of gas and dust. On the right you can see how the shock (outer edge) has injected fingers with motions that are responsible for producing the spin of the disk around the central protostar. Image is provided courtesy of Alan Boss.

    For decades, it’s been hypothesized that our Solar System’s genesis was initiated by a shock wave from a supernova. According to this theory, the wall of pressure formed by a shock wave from the exploding star smacked into a cloud of dust and gas, causing it to collapse and contract into the core of a new proto-star—our Sun. This young Sun was surrounded by a rotating disk of dust and gas that eventually aggregated to form the planets of our Solar System.

    Boss and Keiser have explored this theory of cloud collapse—as opposed to a previous theory of shock wave-caused cloud shredding—using advanced 2-D and 3-D modeling for several years and have published a series of papers supporting it.

    A crucial aspect of this line of research is the distribution of certain products of the explosion, called short-lived radioisotopes. Isotopes are versions of elements that contain the same number of protons, but different number of neutrons. Specific isotopes were formed during the supernova’s explosion and distributed throughout the region that would eventually become our Solar System, before the isotopes had a chance to undergo radioactive decay. Their daughter products can be found today in samples of primitive meteorites.

    Previous modeling work from Boss and Keiser demonstrated that a wave of pressure expanding out from a supernova’s explosion could have struck a gas cloud, and formed little finger-like indentations in the cloud’s surface, which injected the short-lived radioisotopes into the collapsing ball of gas and dust that would eventually become our Sun and its planets.

    The new modeling work from Boss and Keiser shows that this shock injection could have been responsible not only for the distribution of the isotopes now found in primitive meteorites, but also for the spin of our Solar System. The angular momentum of the shock fingers appears to be what allowed the disk of gas and dust to form around the Sun, instead of collapsing into it.

    “This was a complete surprise to me,” Boss said, “the very fact that a rotating disk formed around our proto-Sun may have been a result of the spin induced by this shock front. Without spin, the cloud disappears into the proto-Sun. With spin, a disk suitable for planet formation is created.”

    See the full article here.

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    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

     
  • richardmitnick 11:34 am on February 7, 2015 Permalink | Reply
    Tags: , , , Solar system   

    From Huff Post: “If You Could Tour The Solar System At The Speed Of Light, It Might Look Like This” 

    Huffington Post
    The Huffington Post

    Just how vast is our solar system?

    An eye-opening new animation (above) really puts things in perspective. It shows that even if you travel at the speed of light (186,000 miles per second), the trek from the sun to the Earth and other planets takes a really long time.

    The 45-minute video, created by Los Angeles-based artist Alphonse Swinehart and posted on Vimeo on Jan. 26 [available for download in 720p at YouTube https://www.youtube.com/watch?v=1AAU_btBN7s%5D, starts at the sun and zooms out into the solar system. You reach the Earth and our moon at around 8:20, and the journey ends after reaching Jupiter and its moons (at around 43:20). The distance traveled and time elapsed is visible in the frame’s upper left corner.

    “I’ve taken liberties with certain things like the alignment of planets and asteroids, but overall I’ve kept the size and distances of all the objects as accurate as possible,” Swinehart says in the video’s description. “I also decided to end the animation just past Jupiter as I wanted to keep the running length below an hour.”

    If the video continued on to Saturn, it would have lasted another 34 minutes.

    1

    “I think this is [a] super cool way to understand the enormity of space,” Vimeo user Joe Sullivan commented on the video. “You might want to note… if you were actually a photon traveling at the speed of light you would not experience any time or distance. The time you are expressing is the time as measured by a stationary observer.”

    Now we feel small.

    See the full article here.

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