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 March 23, 2015

News: Obama says more troops will stay in Afghanistan next year - President Obama March 24 formally abandoned his pledge to bring U.S. troop levels in Afghanistan down to 5,000 by the end of this year, saying the current force of about 10,000 will remain there into 2016.   Business: U.S. special ops to sole-source 2,000...
 
 

News Briefs March 25, 2015

Pentagon notifying U.S. troops named by alleged IS hackers The Pentagon said March 23 it is notifying 100 U.S. military members that their names and addresses were posted on the Internet by a group calling itself the Islamic State Hacking Division. The group said it was posting the information, including photos of the individuals, to...
 
 
Courtesy photograph

Lockheed Martin acquires high-speed wind tunnel, plans upgrades

Courtesy photograph A RATTLRS cruise-missile inlet undergoes testing at the High Speed Wind Tunnel at Lockheed Martin Missiles and Fire Control in Grand Prairie. Lockheed Martin recently purchased the facility and plans numerou...
 

 
Lockheed Martin photograph by Andrew McMurtrie

Off they go: Three more C-130Js delivered

Lockheed Martin photograph by Andrew McMurtrie March 19, a U.S. Air Force crew took delivery of and ferried an MC-130J Commando II Special Operations tanker aircraft that is assigned to Air Force Special Operations Command’s ...
 
 

Northrop to provide DIRCM for Canadian Chinook fleet

Northrop Grumman has been selected by the Royal Canadian Air Force to provide infrared missile protection on its fleet of CH-147F Chinooks. “Battle-tested in the harshest conditions and in use around the world, Northrop Grumman’s infrared countermeasure systems have been protecting warfighters for more than 50 years,” said Carl Smith, vice president, infrared countermeasures, ...
 
 

UTC Aerospace awarded contract for surface ship sonar domes

UTC Aerospace Systems has received a contract from the Naval Surface Warfare Center – Crane, Indiana, to provide sonar domes for surface combat ships. The five-year indefinite delivery, indefinite quantity contract is valued at up to $39 million and covers deliveries through 2020 to the U.S. Navy and foreign military sales. In addition to 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>