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  • Hot Cyclones Churn at Both Ends of Saturn
    at NASA s Jet Propulsion Laboratory and co investigator on Cassini s composite infrared spectrometer Since the north pole has been deprived of sunlight since the arrival of winter in 1995 we didn t expect to find a similar feature there The infrared data show that the shadowed north pole vortex shares much the same structure and temperature as the one at the sunny south pole The cores of both show a depletion of phospine gas an imbalance probably caused by air moving downward into the lowest part of Saturn s atmosphere the troposphere Both polar vortices appear to be long lasting and intrinsic parts of Saturn and are not related to the amount of sunlight received by one pole or the other The hot spots are the result of air moving polewards being compressed and heated up as it descends over the poles into the depths of Saturn said Leigh Fletcher a planetary scientist from the University of Oxford England and the lead author of the Science paper The driving forces behind the motion and indeed the global motion of Saturn s atmosphere still need to be understood Though similar the two polar regions differ in one striking way At the north pole the newly discovered vortex is framed by the distinctive long lived and still unexplained polar hexagon This mysterious feature encompassing the entire north pole was first spotted in the 1980s by NASA s Voyager 1 and 2 spacecraft Cassini s infrared cameras also detected the hexagon in deep atmospheric clouds early in 2007 In their paper Fletcher and his colleagues report that the bright warm hexagon is much higher than previous studies had shown It extends right to the top of the troposphere says Fletcher It is associated with downward motion in the troposphere though the

    Original URL path: http://www.lpi.usra.edu/features/saturn/ (2016-02-15)
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  • MESSENGER’s First Look at Mercury’s Previously Unseen Side
    Mercury 2 04 p m EST when the spacecraft was at a distance of about 27 000 kilometers about 17 000 miles The image shows features as small as 10 kilometers 6 miles in size This image was taken through a filter sensitive to light near the red end of the visible spectrum 750 nm one of a sequence of images taken through each of MDIS s 11 filters Like the previously mapped portion of Mercury this hemisphere appears heavily cratered It also reveals some unique and distinctive features On the upper right is the giant Caloris basin including its western portions never before seen by spacecraft Formed by the impact of a large asteroid or comet Caloris is one of the largest and perhaps one of the youngest basins in the solar system The new image shows the complete basin interior and reveals that it is brighter than the surrounding regions and may therefore have a different composition Darker smooth plains completely surround Caloris and many unusual dark rimmed craters are observed inside the basin Several other multi ringed basins are seen in this image for the first time Prominent fault scarps large ridges lace the newly viewed region

    Original URL path: http://www.lpi.usra.edu/features/messenger/01_14_08/ (2016-02-15)
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  • MESSENGER’s First Mercury Flyby Scheduled for January
    To become the first spacecraft to orbit Mercury MESSENGER must follow a path through the inner solar system including one flyby of Earth August 2005 two flybys of Venus October 2006 and June 2007 and three flybys of Mercury January 2008 October 2008 and September 2009 This impressive journey will return the first new data from Mercury in more than 30 years The MESSENGER mission spacecraft and science instruments are focused on answering six key outstanding questions that will allow us to understand Mercury as a planet The data retrieved from MESSENGER should help explain the planet s density geologic history magnetic field and core structure identify any unusual materials at its poles and use measurements of the composition of the exosphere to provide insights into the processes responsible for the planet s existence The average data downlink rate while in Mercury orbit will be 15 megabytes MB per day but the rate will vary enormously during the mission because of the large variation in distance between Mercury and Earth over one year While at Mercury MESSENGER will transmit data for about 80 hours per week Depending on Mercury s location signals from MESSENGER can take anywhere from 4 to

    Original URL path: http://www.lpi.usra.edu/features/messenger/mercury_flyby/ (2016-02-15)
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  • New NASA Mission to Reveal Moon’s Internal Structure and Evolution
    its unsurpassed combination of high scientific value and low technical and programmatic risk Stern said GRAIL also offers to bring innovative Earth studies techniques to the Moon as a precursor to their possible later use at Mars and other planets Scientists will use the gravity field information from the two satellites to X ray the Moon from crust to core to reveal the Moon s subsurface structures and indirectly its thermal history The study technique GRAIL will use was pioneered by the joint U S German Earth observing Gravity Recovery and Climate Experiment GRACE mission which was launched in 2002 The GRACE satellites measure gravity changes related to the movement of mass within Earth such as the melting of ice at the poles and changes in ocean circulation As with GRACE both GRAIL spacecraft will be launched on a single launch vehicle GRAIL s principal investigator is Maria Zuber of the Massachusetts Institute of Technology Zuber s team of expert scientists and engineers includes former NASA astronaut Sally Ride who will lead the mission s public outreach efforts A camera onboard each spacecraft will allow students and the public to interact with observations from the satellites Each GRAIL spacecraft will carry the cameras to documents their views from lunar orbits GRAIL will support NASA s exploration goals as the agency returns humans to the Moon by 2020 In 2008 the agency will launch the Lunar Reconnaissance Orbiter LRO which will circle the Moon for at least a year and take measurements to identify future robotic and human landing sites The orbiter will also look for potential lunar resources and document aspects of the lunar radiation environment After a 30 year hiatus LRO represents NASA s first step toward returning humans to the Moon The orbiter will be accompanied by another

    Original URL path: http://www.lpi.usra.edu/features/moon/grail/ (2016-02-15)
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  • International Group Plans Strategy for Mars Sample Return Mission
    more than half a dozen countries and NASA the European Space Agency ESA the Canadian Space Agency and the Japan Aerospace Exploration Agency JAXA IMARS is a committee of the International Mars Exploration Working Group IMEWG The group was formed in 1993 to provide a forum for the international coordination of Mars exploration missions The potential paradigm changing science from Mars samples makes this mission a high priority of the National Academy of Sciences said Doug McCuistion NASA s Mars Exploration Program director Science Mission Directorate Washington The exciting progress being made by the IMARS team is contributing directly to making this mission a reality in the next decade All spacefaring nations have a standing invitation from IMEWG to participate in IMARS Scientists reviewed past engineering work on a Mars sample return mission international science priorities and sample receiving facility requirements The IMARS team made significant progress in many of the key issues associated with the integration of science and engineering challenges The team established a common strategy for launching a Mars sample return mission and achieving scientific objectives that can be met only by returning martian soil to Earth For Europe this is a major step to shape the

    Original URL path: http://www.lpi.usra.edu/features/mars_sample/ (2016-02-15)
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  • LPI Scientist Part of a Team Reporting Evidence of a Massive Ice Deposit on Mars
    martian surface The findings are based on analysis of data obtained from the Mars Advanced Radar for Subsurface and Ionospheric Sounding MARSIS This instrument which has been in operation since June 2005 utilizes low frequency radar to investigate the nature of the martian subsurface to depths of up to several miles The radar pulses emitted by MARSIS are sensitive to the differences in electromagnetic properties that characterize various geologic materials ice and especially liquid water When a radar pulse encounters the boundary between different materials part of the signal is reflected back to the spacecraft and part continues to propagate deeper into the subsurface with the strength of the reflection proportional to the difference in electromagnetic properties The time that elapses between the transmission of a pulse and the reception of a reflected signal provides a measure of how far below the surface the reflection occurred Using this technique MARSIS scientists investigated a mysterious and extensive equatorial deposit on Mars known as the Medusae Fossae Formation MFF finding it to be as much as two miles deep in some areas Previous investigators have suggested a variety of possible origins for this material ranging from a massive and geologically recent volcanic ash deposit to a relic polar ice cap from a time several billion years ago when the rotational axis of the planet may have been significantly different from that of today Based on a comparison of the strength of the echoes received from the top and bottom of this deposit Clifford and his colleagues concluded that its composition was most consistent with a mixture of large amount of water ice with a small embedded component of dust or volcanic ash although they could not dismiss the possibility of a very low density material Regardless of which interpretation is chosen the

    Original URL path: http://www.lpi.usra.edu/features/mars_ice/clifford/ (2016-02-15)
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  • Graduate Students Eligible for the LPI Career Development Award
    in March The application deadline for the LPI Career Development Award is January 15 2008 Applications should be directed to Dr Stephen Mackwell c o Carol Richardson 3600 Bay Area Boulevard Houston TX 77058 1113 richardson lpi usra edu Applications must include Letter outlining why the applicant would like to participate at the LPSC and what he or she will contribute to the conference Letter of recommendation from his or her research advisor Copy of the first author abstract Curriculum Vita for the applicant The 39th LPSC will be held at the South Shore Harbour Resort and Conference Center in League City Texas An average of 1500 lunar and planetary scientists from all over the world gather each year for the annual meeting which has gained the reputation of being the premiere gathering place for lunar and planetary scientists The LPSC is clearly the must attend meeting of the year said Dr Walter Kiefer staff scientist at the Lunar and Planetary Institute Not only is it the place to get caught up on all the research that s been done over the last year but it provides the best venue at which to have your work presented to the widest

    Original URL path: http://www.lpi.usra.edu/features/cda_award/ (2016-02-15)
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  • Study Sheds New Light on Early Formation of Earth and Mars
    had a primitive atmosphere that acted as the insulator The primitive atmosphere was composed mostly of hydrogen left over from accretion into a rocky planet but was removed probably by impacts about 100 million years after the planet formed says Debaille Debaille and her colleagues performed precise measurements of neodymium isotope compositions of nine rare martian meteorites called shergottites using mass spectrometers at JSC and UCD Shergottites named after the first identified meteorite specimen that fell at Shergotty India in 1865 constitute a class of related meteorites from Mars composed primarily of pyroxene and feldspar The scientists examined shergottites because their large range in chemical compositions is thought to be a fingerprint of the formation of their deep sources very early in the history of Mars These rocks were lavas that were made by melting deep in Mars and that then erupted on the surface said Brandon They were delivered to Earth as meteorites following impacts on Mars that exhumed them and launched them into space Martian meteorites provide a treasure chest of information about the planet Mars and have been the focus of extensive research by scientists The metallic element samarium has two radioactive isotopes that decay at a known rate to two daughter neodymium isotopes By precisely measuring the quantities of neodymium isotopes Debaille was able to use these two radiometric clocks to derive the times of formation of the different shergottite sources in the martian interior We expected to find that their sources all formed at the same time said Debaille But what we found instead was that the shergottite sources formed at two different times The oldest formed at 35 million years after the solar system began to condense from ice and dust into large planets about 4567 million years ago The youngest formed about 100

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