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  • Frictional Heating Explains Plumes on Enceladus
    of the frozen surface of Enceladus and has features called tiger stripes that look like tectonic fault lines We think the tiger stripes are the source of the plumes and we made predictions of where the tiger stripes should be hottest that can be tested by future measurements Nimmo said Driving the whole process is the moon s eccentric orbit which brings it close to Saturn and then farther away so that the gravitational attraction it feels changes over time It s getting squeezed and stretched as it goes around Saturn and those tidal forces cause the faults to move back and forth Nimmo said Unlike some other proposals for the origin of the plumes this mechanism does not require the presence of liquid water near the surface of Enceladus noted co author Robert Pappalardo of NASA s Jet Propulsion Laboratory The heat is sufficient to cause ice to sublimate like in a comet the ice evaporates into vapor and the escaping vapor drags particles off into space Pappalardo said The study does suggest however that Enceladus has a liquid ocean lying deep beneath the ice That allows the ice shell to deform enough to produce the necessary movement in the faults If the ice shell sat directly on top of the moon s rocky interior tidal forces would not produce enough movement in the faults to generate heat Nimmo said The frictional or shear heating mechanism is consistent with an earlier study by Nimmo and Pappalardo that proposed that Enceladus reoriented itself to position its hot spot at the south pole see earlier press release In that study the researchers described how the reorientation of Enceladus would result from a lower density of the thick ice shell in this region In the new paper the researchers estimated the thickness

    Original URL path: http://www.lpi.usra.edu/features/enceladus/plumes/ (2016-02-15)
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  • USGS Releases Clementine NIR Full Resolution Lunar Mosaic
    This Preliminary Release V 0 1 of the full resolution mosaic marks the beginning of the review process by PDS peer reviewers Users of these data should keep in mind that this version remains subject to revision pending the outcome of this review process Website Clementine Near Infrared Global Multispectral Lunar Map These full resolution data are compatible with the previous PDS Clementine UVVIS Full Resolution Digital Image Model available

    Original URL path: http://www.lpi.usra.edu/features/clem_nir/ (2016-02-15)
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  • In Memoriam: Eugene Jarosewich - 1926-2007
    in pursuing these interests he developed the Department s analytical laboratories into a world class facility for the analysis of geological materials Gene is known in the meteoritics community for having accomplished superb wet chemical analyses of meteorites and for developing the only meteorite whole rock standard through his work on specimens of Allende Working with specimens from the National Mineral Collection in the 1970s Gene and his co workers

    Original URL path: http://www.lpi.usra.edu/features/jarosewich/ (2016-02-15)
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  • STEREO Makes First 3-D Images of the Sun
    tangled magnetic fields It s difficult for scientists to tell which structures are in front and which are behind In the solar atmosphere there are no clues to help us judge distance Everything appears flat in the 2 D plane of the sky Having a stereo perspective just makes it so much easier said Dr Russell Howard of the Naval Research Laboratory Washington the Principal Investigator for the SECCHI Sun Earth Connection Coronal and Heliospheric Investigation suite of telescopes on the spacecraft With STEREO s 3 D imagery we ll be able to discern where matter and energy flows in the solar atmosphere much more precisely than with the 2 D views available before This will really help us understand the complex physics going on said Howard STEREO s depth perception also will help improve space weather forecasts Of particular concern is a destructive type of solar eruption called a Coronal Mass Ejection CME CMEs are eruptions of electrically charged gas called plasma from the sun s atmosphere A CME cloud can contain billions of tons of plasma and move at a million miles per hour The CME cloud is laced with magnetic fields and CMEs directed toward Earth smash into our planet s magnetic field If the CME magnetic fields have the proper orientation they dump energy and particles into Earth s magnetic field causing magnetic storms that can overload power line equipment and radiation storms that disrupt satellites Satellite and utility operators can take precautions to minimize CME damage but they need an accurate forecast of when the CME will arrive To do this forecasters need to know the location of the front of the CME cloud STEREO will allow scientists to accurately locate the CME cloud front Knowing where the front of the CME cloud is will

    Original URL path: http://www.lpi.usra.edu/features/3_D_sun/ (2016-02-15)
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  • Molly McCanta, Planetary Detective
    the geological history of the Red Planet With only 37 samples available that s quite a daunting task but McCanta loves the challenge Everyone knows we went to the Moon and that we brought back a lot of samples but not very many people know that we have samples in hand from Mars And we haven t gone there Mars gave them to us to look at explains McCanta At some point in the past something hit Mars with enough force to create a crater and throw off material that traveled through space arriving on Earth in the form of meteorites Scientists know these meteorites came from Mars because of three very distinct pieces of evidence First of all we know these rocks are very young so they had to have come from a planet that had volcanic activity into very near present time something like the Earth and that limits the number of planets in our solar system down to essentially Mars McCanta continues to explain that the other two pieces of evidence are the type of oxygen contained in the rocks which is not the type of oxygen found on Earth and the gas bubbles trapped within them which match the gas compositions measured by the Viking landers when they arrived on the martian surface in the 1970s One of the goals of McCanta s research is to determine where on Mars a meteorite came from or where there are rocks of similar type on Mars We may never be able to say this is the exact crater that this certain meteorite came from but what we can say is that this region has a very similar composition to these meteorites that we have down on Earth and we know the conditions they formed under so we can say something then about the geology of that region on Mars And the challenge Trying to determine the geology of a planet with only 37 samples to work with After all if someone were to give you 37 randomly distributed rocks from the Earth and ask you to tell them how the Earth formed what its geologic history was and what it s doing today that would be a very difficult assignment So that becomes an issue with working with Mars or any other type of planet Because we have only a small amount of information to go on scientists like McCanta try and glean every little bit they can from the rocks they study All the assumptions we make based on these 37 rocks it will be very interesting to see if they hold up when we actually send people there who can walk around the surface and pick up whatever they want While the surface of Mars obviously has similarities to what the Earth was in some respects large volcanos huge valleys that appear to have been channelized with outflows of water it clearly had a very different geologic history The attempt to understand what goes on there

    Original URL path: http://www.lpi.usra.edu/features/mc_canta/ (2016-02-15)
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  • Canada's New Government Appoints New President to the Canadian Space Agency
    said Minister Bernier His leadership experience and dedication will be valuable assets to the continued success of the CSA in developing new space science and technology I would also like to thank Mrs Carole Lacombe Senior Vice President for leading the CSA as Acting President for the past year Her tremendous work and dedication helped strengthen the work of the CSA Mr Boisvert joined Telesat in 1972 where he held several positions He was appointed Vice President of Network Services in 1988 In 1993 he was appointed President and CEO of Telesat Canada In 1997 he became President and CEO of Telesat Mobile Inc while continuing his responsibilities with Telesat Canada Mr Boisvert remained with Telesat until his retirement in 2006 In February 2007 he was inducted into the Society of Satellite Professionals International SSPI in recognition of his many accomplishments over 34 years in the satellite industry He became the second Canadian to be so recognized by the SSPI Mr Boisvert obtained a Radar Technician Certification Diploma from the Royal Canadian Air Force in 1962 He graduated from the Carleton Honours Commerce Program in 1981 Established in 1989 the CSA coordinates all civil space related policies and programs on

    Original URL path: http://www.lpi.usra.edu/features/csa/ (2016-02-15)
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  • Tracking Alien Turbulences with Venus Express
    lies beneath Venus Express is on the contrary capable of looking through the atmosphere at different depths by probing it at different infrared wavelengths The Ultraviolet Visible and Near Infrared Mapping Spectrometer VIRTIS on board is continuing its systematic investigation of Venus atmospheric layers to solve the riddle of the causes for such turbulent and stormy atmosphere The images presented with this article focus on Venusian atmospheric turbulences and cloud features whose shape and size vary with planetary latitudes At the equator clouds are irregular and assume a peculiar bubble shape At mid latitudes they are more regular and streaky running almost parallel to the direction of the super rotation with speed reaching more than 400 kilometers per hour Going higher up in latitude in the polar region the clouds end up in entering a vortex shape With its multi wavelength eyes VIRTIS can observe the atmosphere and the cloud layers not only at different depths but also both in the day and night side of the planet a characteristic that allows an overall assessment of the environmental causes that can be at the origin of such an atmospheric complexity At the equator the extremely violent winds of the super rotation are in constant battle with other kinds of local turbulences or regional winds creating very complex cloud structures One type of regional wind is due to the strong flux of radiation from the Sun reaching the atmosphere of the planet on the day side This flux heats up the atmosphere creating convective cells where masses of warm air move upwards and generate local turbulence and winds On the night side there is obviously no flux from the Sun but the clouds shape and the wind dynamics are somehow similar to that we see on the day side So scientists

    Original URL path: http://www.lpi.usra.edu/features/venus_express/ (2016-02-15)
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  • Smithsonian at the Poles
    150 years ago and resulted in some of the world s foremost collections and archives of Arctic and Antarctic materials The symposium is scheduled for May 3 4 at the Smithsonian s National Museum of Natural History and the Smithsonian Castle in Washington D C The two day event will feature an introductory plenary session followed by concurrent sessions of invited papers and panel discussions evening public and keynote lectures and tours of collections The expected audience includes Smithsonian scholars and research staff university based scientists and students program managers and representatives from federal agencies congressional staff news media and the general public More than 35 scholars will discuss their papers on the following six themes polar astronomy systematics and biology of polar organisms environmental change and polar marine ecosystems IPY histories and legacies methods and techniques of under ice research and cultural studies Sessions will feature disciplinary presentations from both the Arctic and Antarctica Speakers will include research leaders from the Smithsonian and their National Science Foundation supported polar research partners The Smithsonian speakers will represent the Institution s research units Smithsonian Astrophysical Observatory National Museum of Natural History Smithsonian Environmental Research Center National Zoological Park National Air and

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