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NASA's Mars Exploration Rover Spirit is now parked for the winter. The rover team is commanding Spirit this week to make additional preparations for the Mars southern hemisphere winter season. The team does not plan further motion of the wheels until spring comes to Spirit's location beside the western edge of a low plateau called Home Plate. On Sol 2169 (Feb. 8, 2010), the rover's last drive before winter changed the angles of its suspension system, but it did not produce a hoped-for improvement to the overall tilt of the solar array for catching winter sunshine. Drives since Sol 2145 (Jan. 15, 2010) moved Spirit 34 centimeters (13 inches) south-southeastward. However, a counterclockwise yawing of the rover during the drives prevented it from reducing its southerly tilt. Spirit will spend the coming winter tilted 9 degrees toward the south, an unfavorable attitude for the solar panels to catch rays from the sun in the northern sky. Spirit's parking positions for its previous three Martian winters tilted northward. Engineers anticipate that, due to the unfavorable tilt for this fourth winter, Spirit will be out of communication with Earth for several months. Spirit may enter a low-power hibernation mode within a few weeks, shutting down almost all functions except keeping a master clock running and checking its power status periodically until it has enough power to reawaken. It may go in and out of this mode a few times at the beginning and at the end of an extended hibernation period. This week the rover team is uploading schedules to Spirit for when to communicate with Earth or with the orbiting Mars Odyssey during the rest of this year and into 2011. Spirit will use these schedules whenever it has adequate power to wake up. Spirit will take a set of "before" images of surroundings from the parked position this week, for comparison with images in the Martian spring to study effects of wind. Images toward the south will also aid preparations for possible future drives, although, with only four of its six wheels still working, the rover is not expected to move farther than short repositioning drives. Other preparations for winter will include putting the robotic arm into a position for studies of atmospheric composition when power is available and changing the stow positions of the high-gain antenna and panoramic camera to minimize shadowing of the solar panels. Spirit is more than six years into a
mission originally planned for three months on Mars. Its twin,
Opportunity, is exploring an area halfway around the planet and closer to
the equator, where that rover does not need to park for the
winter.
PASADENA, Calif. -- Near the center of a Martian crater about the size of Connecticut, hundreds of exposed rock layers form a mound as tall as the Rockies and reveal a record of major environmental changes on Mars billions of years ago. The history told by this tall parfait of layers inside Gale Crater matches what has been proposed in recent years as the dominant planet-wide pattern for early Mars, according to a new report by geologists using instruments on NASA's Mars Reconnaissance Orbiter. "Looking at the layers from the bottom to the top, from the oldest to the youngest, you see a sequence of changing rocks that resulted from changes in environmental conditions through time," said Ralph Milliken of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This thick sequence of rocks appears to be showing different steps in the drying-out of Mars." Using geological layers to understand stages in the evolution of a planet's climate has a precedent on Earth. A change about 1.8 billion years ago in the types of rock layers formed on Earth became a key to understanding a dramatic change in Earth's ancient atmosphere. Milliken and two co-authors report in Geophysical Research Letters that clay minerals, which form under very wet conditions, are concentrated in layers near the bottom of the Gale stack. Above that, sulfate minerals are intermixed with the clays. Sulfates form in wet conditions and can be deposited when the water in which they are dissolved evaporates. Higher still are sulfate-containing layers without detectable clays. And at the top is a thick formation of regularly spaced layers bearing no detectable water-related minerals. Rock exposures with compositions like various layers of the Gale stack have been mapped elsewhere on Mars, and researchers, including Jean-Pierre Bibring of the University of Paris, have proposed a Martian planetary chronology of clay-producing conditions followed by sulfate-producing conditions followed by dry conditions. However, Gale is the first location where a single series of layers has been found to contain these clues in a clearly defined sequence from older rocks to younger rocks. "If you could stand there, you would see this beautiful formation of Martian sediments laid down in the past, a stratigraphic section that's more than twice the height of the Grand Canyon, though not as steep," said Bradley Thomson of the Johns Hopkins University Applied Physics Laboratory, Laurel, Md. He and John Grotzinger of the California Institute of Technology in Pasadena are Milliken's co-authors. NASA selected Gale Crater in 2008 as one of four finalist sites for the Mars Science Laboratory rover, Curiosity, which has a planned launch in 2011. The finalist sites all have exposures of water-related minerals, and each has attributes that distinguish it from the others. This new report is an example of how observations made for evaluating the landing-site candidates are providing valuable science results even before the rover mission launches. Three instruments on NASA's Mars Reconnaissance Orbiter have provided key data about the layered mound in Gale Crater. Images from the High Resolution Imaging Science Experiment camera reveal details used to map hundreds of layers. Using stereo pairs of the images, the U.S. Geological Survey has generated three-dimensional models used to discern elevation differences as small as a meter (about a yard). Observations by the Compact Reconnaissance Imaging Spectrometer for Mars yielded information about minerals on the surface. The Context Camera provided broader-scale images showing how the layers fit geologically into their surroundings. Thomson said, "This work demonstrates the synergy of the instruments on the Mars Reconnaissance Orbiter. We wouldn't have as complete a picture if we were missing any of the components." The mission has been studying Mars since 2006. It has returned more data from the planet than all other Mars missions combined. More information about this mission is at http://www.nasa.gov/mro. Malin Space Science Systems, San Diego, provided and operates the Context Camera. Johns Hopkins University Applied Physics Laboratory provided and operates the Compact Reconnaissance Imaging Spectrometer. The University of Arizona Lunar and Planetary Laboratory, Tucson, operates the High Resolution Imaging Science Experiment, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. JPL, a division of Caltech, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.
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Make National Voice Your Home Page Missing Children
Code Amber News Service (CANS) issued this Missing Endangered person Alert after the girl disappeared from her bedroom some time after 3 AM Tuesday morning in Satsuma. Satsuma is approximately 75 miles east of Gainsville. Haleigh Cummings a white female, 3 feet tall, weighs 39 pounds and has blond hair and brown eyes. She was last seen wearing a pink shirt and underwear. There are no suspects in this case at this time. However, due to the circumstances of the child's disappearance an abduction is strongly suspected. There is no suspect vehicle at this time. Anyone with information is asked to call the Putnam County Sheriff's office at (386) 329-0808 or dial 911. Download free video of missing Florida child Haleigh Cummings Email this alert to a friend in the area.
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