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  • NASA Decommissions Its Galaxy Hunter Spacecraft
    09 p m EDT Friday June 28 The spacecraft will remain in orbit for at least 65 years then fall to Earth and burn up upon reentering the atmosphere GALEX met its prime objectives and the mission was extended three times before being canceled Highlights from the mission s decade of sky scans include Discovering a gargantuan comet like tail behind a speeding star called Mira Catching a black hole red handed as it munched on a star Finding giant rings of new stars around old dead galaxies Independently confirming the nature of dark energy Discovering a missing link in galaxy evolution the teenage galaxies transitioning from young to old The mission also captured a dazzling collection of snapshots showing everything from ghostly nebulas to a spiral galaxy with huge spidery arms In a first of a kind move for NASA the agency in May 2012 loaned GALEX to the California Institute of Technology in Pasadena which used private funds to continue operating the satellite while NASA retained ownership Since then investigators from around the world have used GALEX to study everything from stars in our own Milky Way galaxy to hundreds of thousands of galaxies 5 billion light years away In the space telescope s last year it scanned across large patches of sky including the bustling bright center of our Milky Way The telescope spent time staring at certain areas of the sky finding exploded stars called supernovae and monitoring how objects such as the centers of active galaxies change over time GALEX also scanned the sky for massive feeding black holes and shock waves from early supernova explosions In the last few years GALEX studied objects we never thought we d be able to observe from the Magellanic clouds to bright nebulae and supernova remnants in the

    Original URL path: http://www.lpi.usra.edu/features/galex/ (2016-02-15)
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  • Voyager 1 Explores Final Frontier of Our “Solar Bubble”
    not know exactly how far Voyager 1 has to go to reach interstellar space They estimate it could take several more months or even years to get there The heliosphere extends at least 8 billion miles beyond all the planets in our solar system It is dominated by the Sun s magnetic field and an ionized wind expanding outward from the Sun Outside the heliosphere interstellar space is filled with matter from other stars and the magnetic field present in the nearby region of the Milky Way Voyager 1 and its twin spacecraft Voyager 2 were launched in 1977 They toured Jupiter Saturn Uranus and Neptune before embarking on their interstellar mission in 1990 They now aim to leave the heliosphere Measuring the size of the heliosphere is part of the Voyagers mission The Science papers focus on observations made from May to September 2012 by Voyager 1 s cosmic ray low energy charged particle and magnetometer instruments with some additional charged particle data obtained through April of this year Voyager 2 is about 9 billion miles from the Sun and still inside the heliosphere Voyager 1 was about 11 billion miles from the Sun on August 25 when it reached the magnetic highway also known as the depletion region and a connection to interstellar space This region allows charged particles to travel into and out of the heliosphere along a smooth magnetic field line instead of bouncing around in all directions as if trapped on local roads For the first time in this region scientists could detect low energy cosmic rays that originate from dying stars We saw a dramatic and rapid disappearance of the solar originating particles They decreased in intensity by more than 1000 times as if there was a huge vacuum pump at the entrance ramp

    Original URL path: http://www.lpi.usra.edu/features/voyager/070813/ (2016-02-15)
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  • Cassini Probe to Take Photo of Earth From Deep Space
    27 p m EDT or 21 27 UTC and end about 15 minutes later all while Saturn is eclipsing the Sun from Cassini s point of view The spacecraft s unique vantage point in Saturn s shadow will provide a special scientific opportunity to look at the planet s rings At the time of the photo North America and part of the Atlantic Ocean will be in sunlight Unlike two previous Cassini eclipse mosaics of the Saturn system in 2006 which captured Earth and another in 2012 the July 19 image will be the first to capture the Saturn system with Earth in natural color as human eyes would see it It also will be the first to capture Earth and its moon with Cassini s highest resolution camera The probe s position will allow it to turn its cameras in the direction of the Sun where Earth will be without damaging the spacecraft s sensitive detectors Ever since we caught sight of the Earth among the rings of Saturn in September 2006 in a mosaic that has become one of Cassini s most beloved images I have wanted to do it all over again only better said Carolyn Porco Cassini imaging team lead at the Space Science Institute in Boulder Colorado This time I wanted to turn the entire event into an opportunity for everyone around the globe to savor the uniqueness of our planet and the preciousness of the life on it Porco and her imaging team associates examined Cassini s planned flight path for the remainder of its Saturn mission in search of a time when Earth would not be obstructed by Saturn or its rings Working with other Cassini team members they found the July 19 opportunity would permit the spacecraft to spend time in Saturn

    Original URL path: http://www.lpi.usra.edu/features/cassini/062413/ (2016-02-15)
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  • LPI Launches Planetary News
    community provided by the LPI Informational news and announcements from NASA international space agencies and other sources are categorized and easily accessed at the Planetary News website Published news and announcements are archived by month and can be retrieved by searching on category date or keyword The website also provides access to LPI s comprehensive calendar of planetary meetings and events Subscribers may opt in to receive weekly e mail

    Original URL path: http://www.lpi.usra.edu/features/planetary_news/ (2016-02-15)
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  • Stars Don’t Obliterate Their Planets (Very Often)
    can bring these giant planets close to their host stars Hot Jupiters are giant balls of gas that resemble Jupiter in mass and composition They don t begin life under the glare of a sun but form in the chilly outer reaches as Jupiter did in our solar system Ultimately the hot Jupiter planets head in toward their stars a relatively rare process still poorly understood The new study answers questions about the end of the hot Jupiters travels revealing what put the brakes on their migration Previously there were a handful of theories explaining how this might occur One theory proposed that the star s magnetic field prevented the planets from going any farther When a star is young a planet forming disk of material surrounds it The material falls into the star a process astronomers call accretion but when it hits the magnetic bubble around it called the magnetosphere the material travels up and around the bubble landing on the star from the top and bottom This bubble could be halting migrating planets so the theory went Another theory held that the planets stopped marching forward when they hit the end of the dusty portion of the planet forming disk This theory basically said that the dust road a planet travels on ends before the planet falls all the way into the star said co author Chris Bilinski of the University of Arizona Tucson A gap forms between the star and the inner edge of its dusty disk where the planets are thought to stop their migration And yet a third theory the one the researchers found to be correct proposed that a migrating planet stops once the star s tidal forces have completed their job of circularizing its orbit To test these and other scenarios the scientists

    Original URL path: http://www.lpi.usra.edu/features/kepler/062413/ (2016-02-15)
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  • Cassini Sees Precursors to Aerosol Haze on Titan
    water in Earth s atmosphere and makes up about 2 of Titan s atmosphere Scientists have speculated that the atmosphere of this moon may resemble that of our planet in its early days before primitive living organisms enriched it with oxygen via photosynthesis When sunlight or highly energetic particles from Saturn s magnetic bubble hit the layers of Titan s atmosphere above about 600 miles 1000 kilometers the nitrogen and methane molecules there are broken up This results in the formation of massive positive ions and electrons which trigger a chain of chemical reactions producing a variety of hydrocarbons a wide range of which have been detected in Titan s atmosphere These reactions eventually lead to the production of carbon based aerosols large aggregates of atoms and molecules that are found in the lower layers of the haze that enshrouds Titan well below 300 miles 500 kilometers The process is similar to Earth where smog starts with sunlight breaking up hydrocarbons that are emitted into the air The resulting pieces recombine to form more complex molecules Aerosols in Titan s lower haze have been studied using data from the descent of the European Space Agency s Huygens probe which reached the surface in 2005 but their origin remained unclear New studies analyzing data from Cassini s visual and infrared mapping spectrometer VIMS gathered in July and August 2007 might solve the problem One new study of Titan s upper atmosphere in the Astrophysical Journal describes the detection of the PAHs which are large carbon based molecules that form from the aggregation of smaller hydrocarbons We can finally confirm that PAHs play a major role in the production of Titan s lower haze and that the chemical reactions leading to the formation of the haze start high up in the atmosphere said the paper s lead author Manuel López Puertas from the Astrophysics Institute of Andalucia in Granada Spain This finding is surprising We had long suspected that PAHs and aerosols were linked in Titan s atmosphere but didn t expect we could prove this with current instruments The team of scientists had been studying the emission from various molecules in Titan s atmosphere when they stumbled upon a peculiar feature in the data One of the characteristic lines in the spectrum from methane emissions had a slightly anomalous shape and the scientists suspected it was hiding something Bianca Maria Dinelli from the Institute of Atmospheric Sciences and Climate part of the National Research Council in Bologna Italy was the lead author of a related paper in the journal Geophysical Research Letters She and her colleagues conducted a painstaking investigation to identify the chemical species responsible for the anomaly The additional signal was found only during daytime so it clearly had something to do with solar irradiation The central wavelength of this signal about 3 28 microns is typical for aromatic compounds hydrocarbon molecules in which the carbon atoms are bound in ring like structures said Dinelli The scientists tested whether

    Original URL path: http://www.lpi.usra.edu/features/cassini/061413/ (2016-02-15)
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  • GRAIL Mission Solves Mystery of Moon’s Surface Gravity
    the May 30 edition of the journal Science GRAIL data confirm that lunar mascons were generated when large asteroids or comets impacted the ancient Moon when its interior was much hotter than it is now said Jay Melosh a GRAIL co investigator at Purdue University in West Lafayette Indiana and lead author of the paper We believe the data from GRAIL show how the Moon s light crust and dense mantle combined with the shock of a large impact to create the distinctive pattern of density anomalies that we recognize as mascons The origin of lunar mascons has been a mystery in planetary science since their discovery in 1968 by a team at NASA s Jet Propulsion Laboratory Researchers generally agree mascons resulted from ancient impacts billions of years ago It was not clear until now how much of the unseen excess mass resulted from lava filling the crater or iron rich mantle upwelling to the crust On a map of the Moon s gravity field a mascon appears in a target pattern The bulls eye has a gravity surplus It is surrounded by a ring with a gravity deficit A ring with a gravity surplus surrounds the bulls eye and the inner ring This pattern arises as a natural consequence of crater excavation collapse and cooling following an impact The increase in density and gravitational pull at a mascon s bulls eye is caused by lunar material melted from the heat of a long ago asteroid impact Knowing about mascons means we finally are beginning to understand the geologic consequences of large impacts Melosh said Our planet suffered similar impacts in its distant past and understanding mascons may teach us more about the ancient Earth perhaps about how plate tectonics got started and what created the first ore deposits

    Original URL path: http://www.lpi.usra.edu/features/grail/061413/ (2016-02-15)
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  • Marks on Martian Dunes May Be Tracks of Dry-Ice Sleds
    sediment downhill and the material eroded from the top is carried to the bottom and deposited as a fan shaped apron said Diniega In the linear gullies you re not transporting material You re carving out a groove pushing material to the sides Images from MRO s High Resolution Imaging Science Experiment HiRISE camera show sand dunes with linear gullies covered by carbon dioxide frost during the martian winter The location of the linear gullies is on dunes that spend the martian winter covered by carbon dioxide frost By comparing before and after images from different seasons researchers determined that the grooves are formed during early spring Some images have even caught bright objects in the gullies Scientists theorize the bright objects are pieces of dry ice that have broken away from points higher on the slope According to the new hypothesis the pits could result from the blocks of dry ice completely sublimating away into carbon dioxide gas after they have stopped traveling Linear gullies don t look like gullies on Earth or other gullies on Mars and this process wouldn t happen on Earth said Diniega You don t get blocks of dry ice on Earth unless you go buy them That is exactly what report co author Candice Hansen of the Planetary Science Institute in Tucson Arizona did Hansen has studied other effects of seasonal carbon dioxide ice on Mars such as spider shaped features that result from explosive release of carbon dioxide gas trapped beneath a sheet of dry ice as the underside of the sheet thaws in spring She suspected a role for dry ice in forming linear gullies so she bought some slabs of dry ice at a supermarket and slid them down sand dunes That day and in several later experiments gaseous carbon

    Original URL path: http://www.lpi.usra.edu/features/mro/061413/ (2016-02-15)
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