Space

September 28, 2012

NASA Mars rover finds old streambed on Martian surface

NASA’s Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence – images of rocks containing ancient streambed gravels – is the first of its kind.

Scientists are studying the images of stones cemented into a layer of conglomerate rock. The sizes and shapes of stones offer clues to the speed and distance of a long-ago stream’s flow.

“From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep,” said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. “Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.”

The finding site lies between the north rim of Gale Crater and the base of Mount Sharp, a mountain inside the crater. Earlier imaging of the region from Mars orbit allows for additional interpretation of the gravel-bearing conglomerate. The imagery shows an alluvial fan of material washed down from the rim, streaked by many apparent channels, sitting uphill of the new finds.

The rounded shape of some stones in the conglomerate indicates long-distance transport from above the rim, where a channel named Peace Vallis feeds into the alluvial fan. The abundance of channels in the fan between the rim and conglomerate suggests flows continued or repeated over a long time, not just once or for a few years.

The discovery comes from examining two outcrops, called “Hottah” and “Link” with the telephoto capability of Curiosity’s mast camera during the first 40 days after landing. Those observations followed up on earlier hints from another outcrop, which was exposed by thruster exhaust as Curiosity, the Mars Science Laboratory Project’s rover, touched down.

“Hottah looks like someone jack-hammered up a slab of city sidewalk, but it’s really a tilted block of an ancient streambed,” said Mars Science Laboratory Project Scientist John Grotzinger of the California Institute of Technology in Pasadena.

The gravels in conglomerates at both outcrops range in size from a grain of sand to a golf ball. Some are angular, but many are rounded.

“The shapes tell you they were transported and the sizes tell you they couldn’t be transported by wind. They were transported by water flow,” said Curiosity science co-investigator Rebecca Williams of the Planetary Science Institute in Tucson, Ariz.

The science team may use Curiosity to learn the elemental composition of the material, which holds the conglomerate together, revealing more characteristics of the wet environment that formed these deposits. The stones in the conglomerate provide a sampling from above the crater rim, so the team may also examine several of them to learn about broader regional geology.

The slope of Mount Sharp in Gale Crater remains the rover’s main destination. Clay and sulfate minerals detected there from orbit can be good preservers of carbon-based organic chemicals that are potential ingredients for life.

“A long-flowing stream can be a habitable environment,” said Grotzinger. “It is not our top choice as an environment for preservation of organics, though. We’re still going to Mount Sharp, but this is insurance that we have already found our first potentially habitable environment.”

During the two-year prime mission of the Mars Science Laboratory, researchers will use Curiosity’s 10 instruments to investigate whether areas in Gale Crater have ever offered environmental conditions favorable for microbial life.

 




All of this week's top headlines to your email every Friday.


 
 

 
Lockheed Martin photograph

Lockheed Martin successfully mates NOAA GOES-R satellite modules

Lockheed Martin photograph Lockheed Martin successfully mated together the large system and propulsion modules of the first GOES-R series weather satellite at the companyís Space Systems facilities near Denver, Colo. A team of...
 
 
Image courtesy of NASA/GSFC

NASA Mars spacecraft ready for Sept. 21 orbit insertion

NASA’s Mars Atmosphere and Volatile Evolution spacecraft is nearing its scheduled Sept. 21 insertion into Martian orbit after completing a 10-month interplanetary journey of 442 million miles. Flight Controllers at Lockheed M...
 
 

Lockheed Martin-built CLIO satellite successfully launched

The U.S. government’s CLIO satellite, designed and built by Lockheed Martin, was successfully launched today from Cape Canaveral Air Force Station, Fla. Lift-off occurred at 6:10 p.m., MDT, aboard a United Launch Alliance Atlas V launch vehicle. Initial contact with the satellite was confirmed at 9:08 p.m., MDT. The CLIO system is based on innovative...
 

 

ULA launches 60th Mission from Cape Canaveral

A United Launch Alliance Atlas V rocket carrying the CLIO mission for Lockheed Martin Space Systems Company launched at 8:10†p.m., EDT, Sept. 16 from Space Launch Complex-41 at Cape Canaveral Air Force Station, Fla. “It is an honor to work with Lockheed Martin Space Systems Company and all of our mission partners to launch this...
 
 
Image courtesy of NASA, ESA, STScI-RCC14-41a

Hubble helps find smallest known galaxy containing supermassive black hole

Image courtesy of NASA, ESA, STScI-RCC14-41a Artist’s View of M60-UCD1 Black Hole.   Astronomers using data from NASA’s Hubble Space Telescope and ground observation have found an unlikely object in an improbable p...
 
 
Image courtesy of NASA/CXC/M. Weiss

NASA’s Chandra X-ray Observatory finds planet that makes star act deceptively old

Image courtesy of NASA/CXC/M. Weiss A new study from NASA’s Chandra X-ray Observatory shows that a giant exoplanet, WASP-18b, is making the star that it orbits very closely act much older than it actually is. This artist&...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>