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  • Scientists Find Evidence of “Diving” Tectonic Plates on Europa
    Europa s surface show evidence of extension where wide bands miles wide formed as the surface ripped apart and fresh icy material from the underlying shell moved into the newly created gap a process akin to seafloor spreading on Earth On Earth as new surface material forms at mid ocean ridges old material is destroyed at subduction zones which are regions where two tectonic plates converge and overlap as one is forced under the other However despite the degree of extension evident on Europa s surface researchers had not been able to determine how the surface could accommodate all the new material Scientists studying Europa often reconstruct the moon s surface blocks into their original configuration as with a jigsaw puzzle to get a picture of what the surface looked like before the disruption occurred When Kattenhorn and Prockter rearranged the icy terrain in the images they discovered that nearly 20 000 square kilometers more than 12 000 square miles of the surface were missing in the moon s high northern latitudes Further evidence suggested the missing terrain moved under a second surface plate a scenario commonly seen on Earth at plate tectonic boundaries Kattenhorn and Prockter saw ice volcanos on the overriding plate possibly formed through melting and absorption of the slab as it dove below the surface and a lack of mountains at the subduction zone implying material was pushed into the interior rather than crumpled up as the two plates mashed against each other The scientists believe the subducted area was absorbed into Europa s ice shell which may be up to 30 kilometers 20 miles thick rather than breaking through it into Europa s underlying ocean On Europa s relatively young surface about 40 90 million years old on average scientists have seen evidence of material

    Original URL path: http://www.lpi.usra.edu/features/europa/092314/ (2016-02-15)
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  • Rosetta Landing Site Search Narrows
    be asked Will the lander be able to maintain regular communications with Rosetta How common are surface hazards such as large boulders deep crevasses or steep slopes Is there sufficient illumination for scientific operations and enough sunlight to recharge the lander s batteries beyond its initial 64 hour lifetime without causing overheating The potential landing sites were assigned a letter from an original preselection of 10 possible sites which does not signify any ranking Three sites B I and J are located on the smaller of the two lobes of the comet and two sites A and C are located on the larger lobe The process of selecting a landing site is extremely complex and dynamic as we get closer to the comet we will see more and more details which will influence the final decision on where and when we can land said Fred Jansen Rosetta s mission manager from the European Space Agency s Science and Technology Centre in Noordwijk The Netherlands We had to complete our preliminary analysis on candidate sites very quickly after arriving at the comet and now we have just a few more weeks to determine the primary site The clock is ticking and we now have to meet the challenge to pick the best possible landing site The next step in preparation for landing operations is a comprehensive analysis of each of the candidate sites to determine possible orbital and operational strategies that could be used for Rosetta to deliver the lander to any of them At the same time Rosetta will move to within 50 kilometers 31 miles of the comet allowing a more detailed study of the proposed landing sites By September 14 the five candidate sites will have been assessed and ranked leading to the selection of a primary landing

    Original URL path: http://www.lpi.usra.edu/features/rosetta/ (2016-02-15)
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  • Stardust Discovers Potential Interstellar Space Particles
    and Training Range 129 kilometers 80 miles west of Salt Lake City The Stardust Sample Return Canister was transported to a curatorial facility at JSC where the Stardust collectors remain preserved and protected for scientific study Inside the canister a tennis racket like sample collector tray captured the particles in silica aerogel as the spacecraft flew within 240 kilometers 149 miles of a comet in January 2004 An opposite side of the tray holds interstellar dust particles captured by the spacecraft during its seven year 4 8 billion kilometer 3 billion mile journey Scientists caution that additional tests must be done before they can say definitively that these are pieces of debris from interstellar space But if they are the particles could help explain the origin and evolution of interstellar dust The particles are much more diverse in terms of chemical composition and structure than scientists expected The smaller particles differ greatly from the larger ones and appear to have varying histories Many of the larger particles have been described as having a fluffy structure similar to a snowflake Two particles each only about 2 micrometers thousandths of a millimeter or 0 04 inches in diameter were isolated after their tracks were discovered by a group of citizen scientists These volunteers who call themselves Dusters scanned more than a million images as part of a University of California Berkeley UC Berkeley citizen science project which proved critical to finding these needles in a haystack A third track following the direction of the wind during flight was left by a particle that apparently was moving so fast more than 15 kilometers 10 miles per second that it vaporized Volunteers identified tracks left by another 29 particles that were determined to have been kicked out of the spacecraft into the collectors Four

    Original URL path: http://www.lpi.usra.edu/features/stardust/082614/ (2016-02-15)
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  • Voyager Map Details Neptune’s Strange Moon Triton
    and blue filter images In 1989 most of the northern hemisphere was in darkness and unseen by Voyager Because of the speed of Voyager s visit and the slow rotation of Triton only one hemisphere was seen clearly at close distance The rest of the surface was either in darkness or seen as blurry markings The production of the new Triton map was inspired by anticipation of NASA s New Horizons encounter with Pluto coming up a little under a year from now Among the improvements on the map are updates to the accuracy of feature locations sharpening of feature details by removing some of the blurring effects of the camera and improved color processing Although Triton is a moon of a planet and Pluto is a dwarf planet Triton serves as a preview of sorts for the upcoming Pluto encounter Although both bodies originated in the outer solar system Triton was captured by Neptune and has undergone a radically different thermal history than Pluto Tidal heating has likely melted the interior of Triton producing the volcanos fractures and other geological features that Voyager saw on that bitterly cold icy surface Pluto is unlikely to be a copy of Triton but some of the same types of features may be present Triton is slightly larger than Pluto has a very similar internal density and bulk composition and has the same low temperature volatiles frozen on its surface The surface composition of both bodies includes carbon monoxide carbon dioxide methane and nitrogen ices Voyager also discovered atmospheric plumes on Triton making it one of the known active bodies in the outer solar system along with objects such as Jupiter s moon Io and Saturn s moon Enceladus Scientists will be looking at Pluto next year to see if it will join

    Original URL path: http://www.lpi.usra.edu/features/voyager/082614/ (2016-02-15)
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  • Illustrating Bombardment of Early Earth by Asteroids
    study Simone Marchi of the Southwest Research Institute in Boulder Colorado created two animated GIF movies to illustrate the Hadean period of asteroid bombardment The Center for Lunar Science and Exploration a division of the Lunar and Planetary Institute is posting those movies for students faculty and the general public to utilize at www lpi usra edu exploration HadeanEarth Links to other illustrations of the early Earth are also available on that education resource page This work is part of a systematic study of the early Earth and the impact events that may have affected the origin and early evolution of life on Earth being led by David A Kring of the Lunar and Planetary Institute in Houston Texas one of the co authors of the new study and principal investigator of the Center for Lunar Science and Exploration The detailed modeling that Dr Marchi and the team have done greatly clarifies the events that shaped the Hadean Earth he said We are glad we can distribute classroom resources that illustrate the consequences of impact cratering which is one of the most important planetary processes in the solar system A suite of classroom resources related to the evolution of the

    Original URL path: http://www.lpi.usra.edu/features/bombardment/ (2016-02-15)
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  • LPI Science Research Staff Announced as SSERVI Award Winners
    the Smithsonian Library of the Solar System series and co author of The Clementine Atlas of the Moon by Cambridge University Press Spudis is also a team member with the Center for Lunar Science and Exploration CLSE a SSERVI team based at the LPI that is a collaborative effort between LPI and the NASA Johnson Space Center JSC Spudis joins Jeff Taylor 2011 recipient and current CLSE team member and Ross Taylor 2012 recipient and former LPI visiting scientist and Heritage Fellow as a recipient of this very distinguished medal This year SSERVI established the Susan Mahan Niebur Early Career Award which is an annual award given to an early career scientist who has made significant contributions to the science or exploration communities This year the prize was presented to two individuals Simone Marchi of the Southwest Research Institute SwRI and LPI Katherine Joy also from the LPI The recipients are both researchers who are ten years out or less from their Ph D who have shown excellence in their field and demonstrated meaningful contributions to the science or exploration communities Joy investigates the crust formation processes impacts and space environment interactions in the evolution of planetary bodies using geochemical and chronological sample analysis and remote sensing data She is an Early Career Postdoctoral Research Fellow at the University of Manchester and was previously a Postdoctoral Fellow at the LPI and JSC She is involved with several international planetary science missions including Co Investigator Co I for the Demonstration of a Compact Imaging X ray Spectrometer D CIXS Co I for the Chandrayaan 1 X ray Spectrometer C1XS and Co I for the Mercury Imaging X ray Spectrometer MIXS instrument that will fly onboard ESA s BepiColumbo mission to Mercury Her many awards include the 2013 Royal Astronomical Society s

    Original URL path: http://www.lpi.usra.edu/features/sservi/072114/ (2016-02-15)
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  • Cassini Celebrates 10 Years Exploring Saturn
    have been privileged to witness never before seen events that are changing our understanding of how planetary systems form and what conditions might lead to habitats for life After 10 years at Saturn the stalwart spacecraft has beamed back to Earth hundreds of gigabytes of scientific data enabling the publication of more than 3000 scientific reports Representing just a sampling 10 of Cassini s top accomplishments and discoveries are 1 The Huygens probe makes first landing on a moon in the outer solar system Titan 2 Discovery of active icy plumes on the saturnian moon Enceladus 3 Saturn s rings revealed as active and dynamic a laboratory for how planets form 4 Titan revealed as an Earth like world with rain rivers lakes and seas 5 Studies of Saturn s great northern storm of 2010 2011 6 Studies reveal radio wave patterns are not tied to Saturn s interior rotation as previously thought 7 Vertical structures in the rings imaged for the first time 8 Study of prebiotic chemistry on Titan 9 Mystery of the dual bright dark surface of the moon Iapetus solved 10 First complete view of the north polar hexagon and discovery of giant hurricanes at both of Saturn s poles It s incredibly difficult to sum up 10 extraordinary years of discovery in a short list but it s an interesting exercise to think about what the mission will be best remembered for many years in the future Spilker said Further details about each of these top 10 discoveries are available at saturn jpl nasa gov news cassinifeatures 10thannivdiscoveries In celebration of the 10th anniversary members of the Cassini team selected some of their favorite images for a gallery describing in their own words what makes the images special to them The gallery is available at

    Original URL path: http://www.lpi.usra.edu/features/cassini/070814/ (2016-02-15)
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  • Ocean on Saturn Moon Could be as Salty as the Dead Sea
    in the journal Icarus Additional findings support previous indications the moon s icy shell is rigid and in the process of freezing solid Researchers found that a relatively high density was required for Titan s ocean in order to explain the gravity data This indicates the ocean is probably an extremely salty brine of water mixed with dissolved salts likely composed of sulfur sodium and potassium The density indicated for this brine would give the ocean a salt content roughly equal to the saltiest bodies of water on Earth This is an extremely salty ocean by Earth standards said the paper s lead author Giuseppe Mitri of the University of Nantes in France Knowing this may change the way we view this ocean as a possible abode for present day life but conditions might have been very different there in the past Cassini data also indicate the thickness of Titan s ice crust varies slightly from place to place The researchers said this can best be explained if the moon s outer shell is stiff as would be the case if the ocean were slowly crystalizing and turning to ice Otherwise the moon s shape would tend to even itself out over time like warm candle wax This freezing process would have important implications for the habitability of Titan s ocean as it would limit the ability of materials to exchange between the surface and the ocean A further consequence of a rigid ice shell according to the study is any outgassing of methane into Titan s atmosphere must happen at scattered hot spots like the hot spot on Earth that gave rise to the Hawaiian Island chain Titan s methane does not appear to result from convection or plate tectonics recycling its ice shell How methane gets into the

    Original URL path: http://www.lpi.usra.edu/features/cassini/070814-2/ (2016-02-15)
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