Thursday 25 October 2007

Teknologi Kapal Luar Angkasa V








Mars Orbiter Examines 'Lace' and 'Lizard Skin' Terrain




Added and Edited By:
Arip Nurahman Department of Physics, Faculty of sciences and Mathematics
Indonesia University of Education
&
Follower Open Course Ware at MIT-Harvard University, U.S.A.


Calendar / Announcements


11.12.09 Lecture series: Taking a Closer Look at Exoplanet Atmospheres
11.12.09 Teacher workshop: Lunar Certification
11.14.09 Teacher workshop: Connecting With Climate Change
12.03.09 Lecture series: Monitoring Earth's Changing Land Surface



SAN FRANCISCO - Scrutiny by NASA's newest Mars orbiter is helping scientists learn the stories of some of the weirdest landscapes on Mars, as well as more familiar-looking parts of the Red Planet.

One type of landscape near Mars' south pole is called "cryptic terrain" because it once defied explanation, but new observations bolster and refine recent interpretations of how springtime outbursts of carbon-dioxide gas there sculpt intricate patterns and paint seasonal splotches.

"A lot of Mars looks like Utah, but this is an area that looks nothing like Planet Earth," said Candice Hansen of NASA's Jet Propulsion Laboratory, Pasadena, Calif., deputy principal investigator for the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

In addition to radially branching patterns called "spiders," which had been detected by an earlier Mars orbiter, other intriguing ground textures in the area appear in the new images. "In some places, the channels form patterns more like lace. In others, the texture is reminiscent of lizard skin," Hansen said.

Results from all six instruments on the Mars Reconnaissance Orbiter, which reached Mars last year, are described in dozens of presentations this week by planetary scientists in San Francisco at the fall meeting of the American Geophysical Union.

This is a perspective view of a scene within Mars' Candor Chasma. It shows how the surface would appear to a person standing on top of one of the many hills in the region and facing southeast. Image credit: NASA/JPL/University of Arizona
› Full image and caption
By taking stereo pictures of a target area from slightly different angles during different orbits, HiRISE can show the surface in three dimensions. Channels found to widen as they run uphill in the cryptic terrain region testify that the channels are cut by a gas, not a liquid.

Earlier evidence for jets of gas active in the region came from fan-shaped blotches appearing seasonally, which scientists interpret as material fallen to the surface downwind of vents where the gas escapes. Some of the fans are dark, others bright. "The dark fans are probably dust, but the exact composition of the brighter fans had remained unknown until now," said Tim Titus of the U.S. Geological Survey's Astrogeology Team, Flagstaff, Ariz.

Observations by the new orbiter's Compact Reconnaissance Imaging Spectrometer for Mars suggest that the bright fans are composed of carbon-dioxide frost. Here's the story researchers now propose: Spring warms the ground under a winter-formed coating of carbon dioxide ice. Thawing at the base of the coating generates carbon-dioxide gas, which carves channels as it pushes its way under the ice to a weak spot where it bursts free. The jet of escaping gas carries dust aloft and also cools so fast from expanding rapidly that a fraction of the carbon dioxide refreezes and falls back to the surface as frost.

The processes creating the cryptic terrain are current events on Mars. Repeated HiRISE observations of the same target area show the downwind fans can form and grow perceptibly in less than five days.

Other new findings from the Mars Reconnaissance Orbiter reveal processes of Martian environments long ago. A team including Chris Okubo of the University of Arizona, Tucson, used stereo HiRISE images to examine layered deposits inside Mars' Candor Chasma, part of Valles Marineris, the largest canyon system in the solar system.

"The high-resolution structural map allowed us to interpret the geological history of the area," Okubo said. "The layers are tilted in a way that tells us they are younger than the canyon." Spectrometer studies of the composition of these deposits had indicated water played a role in their formation, but their age relative to the formation of the canyon had been uncertain. The new findings suggest water was present after the canyon formed.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter mission for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The University of Arizona operates the HiRISE camera, which was built by Ball Aerospace and Technology Corp., Boulder, Colo. The Compact Reconnaissance Imaging Spectrometer for Mars team, led by Johns Hopkins University's Applied Physics Laboratory, includes expertise from universities, government agencies and small businesses in the United States and abroad.



JPL HIGHER EDUCATION

JPL's Higher Education Group facilitates interactions among colleges and universities (including Caltech) and NASA's Education Office to develop and administer educational programs and research opportunities. The goal is to promote a deeper understanding of the NASA mission by all participants and inspire them to pursue related careers or projects in science, engineering, and technology.

Undergraduate student working with test Rovers While at JPL, most of the participants are JPL affiliates, not JPL employees, and most of their activities take place during several weeks of the summer. All of the programs have eligibility requirements and schedules that applicants must meet in order to be accepted, and awards are competitive.

To get started, visit Find Your Place at JPL, a site geared for students and professionals who are interested in finding out how their field of study fits into JPL’s matrix environment.

The Pre-college Bridge Programs are for students just graduated from high school and on their way to college but not yet enrolled.

The Undergraduate Student Programs offer research challenges to rising college sophomores, juniors, and seniors.

The Graduate Student Programs are for students pursuing degrees beyond the baccalaureate who seek opportunities for summer research projects or for extended collaboration with JPL technical staff tied to their graduate research projects.

The Postdoctoral Programs are primarily, but not solely, for recent recipients of doctoral degrees who are looking for extended research opportunities [two to three years] before accepting or returning to permanent positions in industry, academia, or at federally-funded research and development centers like JPL.

The Faculty Programs accept people in teaching and/or research positions at U. S. academic institutions who want to collaborate with JPL technical staff for professional advancement or to enhance their effectiveness as teachers.

Research Affiliate positions are available to selected scholars able to spend time at JPL conducting projects in concert with JPL technical staff.

A variety of Minority University Programs offer opportunities not different in kind from those mentioned above, but with different sources of support and with the emphasis on increasing the diversity of the NASA/JPL workforce.

Student Employment opportunities

Sumber:

Media Contact: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Arip Nurahman

Semoga Bermanfaat!