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.


 
 

 

Headlines April 17, 2015

News: Army extends benefits to Hood shooting victims¬†- The Army will provide “all possible benefits” to victims of the 2009 Fort Hood shooting who recently were awarded the Purple Heart, the service announced April 16.   Business: Rolls-Royce lands biggest deal in its 109-year history¬†- U.K. engineering company Rolls-Royce has won the largest order in...
 
 

News Briefs April 17, 2015

Army orders financial benefits for 2009 Fort Hood victims Dozens of soldiers and surviving family members of the 2009 Fort Hood, Texas, shooting are receiving additional Army pay that they felt was long overdue. The announcement from Army Sec. John McHugh April 16 comes a week after 36 Purple Hearts were awarded to victims and...
 
 
NASA illustration

NASA awards radiation challenge winners, launches next round

NASA illustration This illustration depicts our heliosphere, showing the approximate locations of Voyager 1 and Voyager 2 spacecraft. Galactic cosmic rays originate outside the heliosphere and stream in uniformly from all direc...
 

 

U.S. Air Force completes operational testing on Raytheon’s MALD-J

Raytheon and the U.S. Air Force successfully completed operational tests of Miniature Air Launched Decoy-Jammer, satisfying all requirements to attain Initial Operational Capability. “MALD-J’s unique capabilities have been proven in 42 successful flight tests during the last two years and brought us closer to full rate production,” said Mike Jarrett, vice president of Raytheon...
 
 

Northrop Grumman to expand North Dakota presence

In partnership with local leadership, Northrop Grumman confirmed its dedication to the future of unmanned systems development in the Red River Valley region by signing a lease agreement to anchor the new Grand Sky Technology Park in Grand Forks County. Northrop Grumman is working to identify specialized opportunities for the Grand Sky facility. The opportunities,...
 
 

Raytheon awarded more than $2 billion for an International Patriot system

Raytheon announced April 17 it has been awarded a contract worth over $2.0 billion to deliver the combat-proven Patriot Air and Missile Defense System to an undisclosed international customer. The contract, awarded April 2, 2015, and booked in the second quarter as a direct commercial sale, includes fully digitized new-production Patriot fire units with the...
 




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>