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  • What Happened to Early Mars’ Atmosphere? New Study Eliminates One Theory
    original atmosphere Instead these missions have found low concentrations of carbonate distributed widely and only a few concentrated deposits By far the largest known carbonate rich deposit on Mars covers an area at least the size of Delaware and maybe as large as Arizona in a region called Nili Fossae Christopher Edwards a former Caltech researcher now with the U S Geological Survey in Flagstaff Arizona and Ehlmann reported the findings and analysis in a paper posted online by the journal Geology Their estimate of how much carbon is locked into the Nili Fossae carbonate deposit uses observations from numerous Mars missions including the Thermal Emission Spectrometer TES on NASA s Mars Global Surveyor orbiter the mineral mapping Compact Reconnaissance Imaging Spectrometer for Mars CRISM and two telescopic cameras on NASA s Mars Reconnaissance Orbiter and the Thermal Emission Imaging System THEMIS on NASA s Mars Odyssey orbiter Edwards and Ehlmann compare their tally of sequestered carbon at Nili Fossae to what would be needed to account for an early Mars atmosphere dense enough to sustain surface waters during the period when flowing rivers left their mark by cutting extensive river valley networks By their estimate it would require more than 35 carbonate deposits the size of the one examined at Nili Fossae They deem it unlikely that so many large deposits have been overlooked in numerous detailed orbiter surveys of the planet While deposits from an even earlier time in Mars history could be deeper and better hidden they don t help solve the thin atmosphere conundrum at the time the river cut valleys formed The modern martian atmosphere is too tenuous for liquid water to persist on the surface A denser atmosphere on ancient Mars could have kept water from immediately evaporating It could also have allowed parts

    Original URL path: http://www.lpi.usra.edu/features/090415/mars/ (2016-02-15)
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  • One Decade After Launch, Mars Orbiter Still Going Strong
    The 27 minute burn of the spacecraft s main engines necessary for orbit capture was scheduled for completion while the spacecraft was behind Mars so we had to wait in suspense for confirmation that it went well It did As planned the initial orbit was highly elliptical Then we had nearly five months of aerobraking using controlled friction of more than 400 dips into the upper fringe of the atmosphere to shrink the orbit to a nearly circular shape MRO s primary science mission began in November 2006 and lasted for one Mars year equivalent to about two Earth years The orbiter has used six instruments to examine Mars surface subsurface and atmosphere The spacecraft has been orbiting Mars at an altitude of about 300 kilometers 186 miles above the Red Planet passing near the north and south poles about 12 times a day Mars Reconnaissance Orbiter has found evidence of diverse watery environments on early Mars some more habitable than others said the mission s project scientist Rich Zurek of NASA s Jet Propulsion Laboratory JPL Pasadena California MRO has discovered that Mars south polar cap holds enough buried carbon dioxide ice to double the planet s current atmosphere if it warmed It s caught avalanches and dust storms in action The spacecraft s longevity has made it possible to study seasonal and longer term changes over four martian years These studies document activity such as moving dunes freshly excavated impact craters some which expose subsurface ice and mysterious strips that darken and fade with the seasons and are best explained as brine flows Although it has already served longer than planned the spacecraft could remain a cornerstone of NASA s Mars Exploration Program fleet for years to come In addition to continuing to make its own discoveries about

    Original URL path: http://www.lpi.usra.edu/features/081315/mro/ (2016-02-15)
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  • New Horizons Team Finds Haze, Flowing Ice on Pluto
    Institute SwRI in Boulder Colorado It reminds us that exploration brings us more than just incredible discoveries it brings incredible beauty Studying Pluto s atmosphere provides clues as to what s happening below The hazes detected in this image are a key element in creating the complex hydrocarbon compounds that give Pluto s surface its reddish hue said Michael Summers New Horizons co investigator at George Mason University in Fairfax Virginia Models suggest the hazes form when ultraviolet sunlight breaks up methane gas particles a simple hydrocarbon in Pluto s atmosphere The breakdown of methane triggers the buildup of more complex hydrocarbon gases such as ethylene and acetylene which also were discovered in Pluto s atmosphere by New Horizons As these hydrocarbons fall to the lower colder parts of the atmosphere they condense into ice particles that create the hazes Ultraviolet sunlight chemically converts hazes into tholins the dark hydrocarbons that color Pluto s surface Scientists previously had calculated temperatures would be too warm for hazes to form at altitudes higher than 30 kilometers 20 miles above Pluto s surface We re going to need some new ideas to figure out what s going on said Summers The New Horizons mission also found in LORRI images evidence of exotic ices flowing across Pluto s surface and revealing signs of recent geologic activity something scientists hoped to find but didn t expect The new images show fascinating details within the Texas sized plain informally named Sputnik Planum which lies within the western half of Pluto s heart shaped feature known as Tombaugh Regio There a sheet of ice clearly appears to have flowed and may still be flowing in a manner similar to glaciers on Earth We ve only seen surfaces like this on active worlds like Earth and Mars said

    Original URL path: http://www.lpi.usra.edu/features/072915/new-horizons/ (2016-02-15)
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  • Could “Windbots” Someday Explore the Skies of Jupiter?
    or create lift Adrian Stoica principal investigator for the windbots study at JPL points to a great example to think about from nature a dandelion seed A dandelion seed is great at staying airborne It rotates as it falls creating lift which allows it to stay afloat for long time carried by the wind We ll be exploring this effect on windbot designs Stoica and colleagues think that to stay airborne for a long time a windbot would need to be able to use energy available in the planet s atmosphere That energy might not be solar because the probe could find itself on the planet s night side for an extended period Nuclear power sources also could be a liability for a floating probe because of their weight But winds temperature variations and even a planet s magnetic field could potentially be sources of energy an atmospheric probe could exploit As they begin their study the team suspects the best bet for an atmospheric robot to harvest energy is turbulence wind that s frequently changing direction and intensity The key is variability High wind velocity isn t enough But in a dynamic turbulent environment there are gradients differences in energy from high to low that can be used It s a spring of energy a probe could drink from said Stoica who thinks a windbot might generate power in a similar way to some wristwatches that can be wound by shaking Embracing turbulence to make power and stay aloft is a departure from the approach taken by conventional aircraft which carry their own internal power sources and perform best in smooth air Commercial airliners for example cruise in Earth s stratosphere where winds tend to be much smoother and flow faster than in the dense air closer to the ground The JPL team is starting out by characterizing winds among the clouds of Jupiter to understand what kinds of places might be best for sending a windbot and to determine some of the technical requirements for its design There are lots of things we don t know Stoica said Does a windbot need to be 10 meters in diameter or 100 How much lift do we need from the winds in order to keep a windbot aloft One thing the team is pretty certain of is that a windbot would need to be able to sense the winds around itself in order to live off the turbulence To that end they plan to build a simple windbot model as part of their study The aerodynamic modeling for this type of craft is particularly difficult so Stoica thinks having a physical model will be important The model windbot would be subjected to carefully controlled turbulent airflows to determine how best to design systems that react and reorient the robot to keep it aloft After that the team would move on to investigating means such as electronic sensors for a windbot to perceive the wind field in the environment around itself

    Original URL path: http://www.lpi.usra.edu/features/072915/windbots/ (2016-02-15)
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  • NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth
    its parent star Kepler 452 than Earth is from the Sun Kepler 452 is 6 billion years old 1 5 billion years older than our Sun has the same temperature is 20 brighter and has a diameter 10 larger We can think of Kepler 452b as an older biggercousin to Earth providing an opportunity to understand and reflect upon Earth s evolving environment said Jon Jenkins Kepler data analysis lead at NASA s Ames Research Center in Moffett Field California who led the team that discovered Kepler 452b It s awe inspiring to consider that this planet has spent 6 billion years in the habitable zone of its star longer than Earth That s substantial opportunity for life to arise should all the necessary ingredients and conditions for life exist on this planet To help confirm the finding and better determine the properties of the Kepler 452 system the team conducted groundbased observations at the University of Texas at Austin s McDonald Observatory the Fred Lawrence Whipple Observatory on Mt Hopkins Arizona and the W M Keck Observatory atop Mauna Kea in Hawaii These measurements were key for the researchers to confirm the planetary nature of Kepler 452b to refine the size and brightness of its host star and to better pin down the size of the planet and its orbit The Kepler 452 system is located 1400 light years away in the constellation Cygnus The research paper reporting this finding has been accepted for publication in the Astronomical Journal In addition to confirming Kepler 452b the Kepler team has increased the number of new exoplanet candidates by 521 from their analysis of observations conducted from May 2009 to May 2013 raising the number of planet candidates detected by the Kepler mission to 4696 Candidates require follow up observations and

    Original URL path: http://www.lpi.usra.edu/features/072915/kepler/ (2016-02-15)
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  • Journey to Pluto Reaches Historic Encounter
    journey of discovery continues The exploration of Pluto and its moons by New Horizons represents the capstone event to 50 years of planetary exploration by NASA and the United States said NASA Administrator Charles Bolden Once again we have achieved a historic first The United States is the first nation to reach Pluto and with this mission has completed the initial survey of our solar system a remarkable accomplishment that no other nation can match Per the plan the spacecraft currently is in data gathering mode and not in contact with flight controllers at the Johns Hopkins University Applied Physical Laboratory APL in Laurel Maryland Scientists are waiting to find out whether New Horizons phones home transmitting to Earth a series of status updates that indicate the spacecraft survived the flyby and is in good health The call is expected shortly after 9 00 p m Eastern Time tonight The Pluto story began only a generation ago when young Clyde Tombaugh was tasked to look for Planet X theorized to exist beyond the orbit of Neptune He discovered a faint point of light that we now see as a complex and fascinating world Pluto was discovered just 85 years ago by a farmer s son from Kansas inspired by a visionary from Boston using a telescope in Flagstaff Arizona said John Grunsfeld associate administrator for NASA s Science Mission Directorate in Washington Today science takes a great leap observing the Pluto system up close and flying into a new frontier that will help us better understand the origins of the solar system New Horizons flyby of the dwarf planet and its five known moons is providing an up close introduction to the solar system s Kuiper belt an outer region populated by icy objects ranging in size from boulders to dwarf planets Kuiper belt objects such as Pluto preserve evidence about the early formation of the solar system New Horizons principal investigator Alan Stern of the Southwest Research Institute SwRI in Boulder Colorado says the mission now is writing the textbook on Pluto The New Horizons team is proud to have accomplished the first exploration of the Pluto system Stern said This mission has inspired people across the world with the excitement of exploration and what humankind can achieve New Horizons almost 10 year five billion kilometer three billion mile journey to closest approach at Pluto took about one minute less than predicted when the craft was launched in January 2006 The spacecraft threaded the needle through a 60 90 kilometer 36 57 mile window in space the equivalent of a commercial airliner arriving no more off target than the width of a tennis ball Because New Horizons is the fastest spacecraft ever launched hurtling through the Pluto system at more than 50 000 kilometers per hour more than 30 000 miles per hour a collision with a particle as small as a grain of rice could incapacitate the spacecraft Once it reestablishes contact Tuesday night it will take 16

    Original URL path: http://www.lpi.usra.edu/features/071415/new-horizons/ (2016-02-15)
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  • Veteran NASA Spacecraft Nears 60,000th Lap Around Mars, No Pit Stops
    and observation of seasonal and year to year changes such as freezing and thawing of carbon dioxide Through its many accomplishments the spacecraft also has aided NASA s preparations for human missions to Mars by monitoring radiation in the environment around the planet via the Mars Radiation Environment Experiment developed at NASA s Johnson Space Center in Houston Odyssey currently is completing an adjustment to an orbit that will position it to pass over martian terrain lit by early morning sunlight rather than afternoon light In its current orbit the spacecraft always flies near each pole and along what is called the terminator The terminator is a line encircling Mars that passes through any point on the planet s surface at sunrise and again at sunset separating the portion of Mars lit by the Sun from the portion experiencing darkness dividing day and night The position of this line varies by time of day and time of year Upcoming observations will focus on what is happening in the martian atmosphere in the morning such as clouds hazes and fogs and on frosts on the surface that burn off by later in the day said Jeffrey Plaut Odyssey project scientist at JPL The planned drift to a morning daylight orbit began in 2012 was accelerated in 2014 and will be completed with a maneuver in November to lock in the orbit timing so that each pass over the equator occurs at the same time of day We have performed many orbit maneuvers over the long life of this mission and we will use that experience conducting the one to halt the drift said Steve Sanders Odyssey spacecraft engineer at Lockheed Martin Space Systems in Denver To date Odyssey s Thermal Emission Imaging System THEMIS has yielded 208 240 images in visible

    Original URL path: http://www.lpi.usra.edu/features/070215/marsOdyssey/ (2016-02-15)
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  • Rosetta’s MIRO Instrument Maps Comet Water
    when Rosetta was 58 kilometers 36 miles from the center of the comet the MIRO team obtained their first map of the nucleus of 67P C G and its surroundings They discovered the highest density of water just above the comet s neck close to the north pole of the comet s rotation axis In this narrow region the number of water molecules is up to two orders of magnitude higher than elsewhere in the coma Lower but still substantial amounts of water were detected over on the dayside of the nucleus up to the terminator between the illuminated and darkside The lowest amounts of water are found on the comet s nightside particularly over its southern polar regions This could be due to either local outgassing or circulation effects within the coma causing water to flow from the day to the nightside The MIRO instrument is a small and lightweight spectrometer that can map the abundance temperature and velocity of cometary water vapor and other molecules that the nucleus releases It can also measure the temperature up to about 2 centimeters 1 inch below the surface of the comet s nucleus One reason the subsurface temperature is important is that the observed gases likely come from sublimating ices beneath the surface By combining information on both the gas and the subsurface MIRO is able to study this process in detail Comets are time capsules containing primitive material left over from the epoch when the Sun and its planets formed Rosetta is the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the Sun s radiation Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in

    Original URL path: http://www.lpi.usra.edu/features/070215/rosetta/ (2016-02-15)
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