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 June 29, 2015

News: SpaceX Falcon 9 explodes moments after launch – A SpaceX rocket carrying supplies to the International Space Station blew up June 28 shortly after liftoff.   Business: How serious a setback is SpaceX rocket explosion? – Elon Musk had never come face to face with that rule before — at least not in space travel —...
 
 

News Briefs June 29, 2015

Iraqi pilot in Arizona plane crash found dead Officials say the body of an Iraqi pilot who had been training in the United States and crashed in southern Arizona has been located. Iraq’s Defense Ministry said June 26 that search teams found the body of Brig. Gen. Rasid Mohammed Sadeeq at the crash site five...
 
 
Huntington Ingalls Industries photograph

PCU John Warner delivered to Navy

Huntington Ingalls Industries photograph A dolphin jumps in front of the Virginia-class attack submarine Pre-Commissioning Unit (PCU) John Warner (SSN 785) as the boat conducts sea trials in the Atlantic Ocean. The U.S. Navy ac...
 

 
navair-helo

HX-21 completes first flight with developmental electronic warfare pod

On June 8, 2015, a UH-1Y from Air Test and Evaluation Squadron (HX) 21 completed the first test flight with a developmental electronic warfare pod.  The pod would represent a new tactical capability for U.S. Marine Corps rotar...
 
 

Northrop, Navy celebrate legacy of EA-6B Prowler

Northrop Grumman photograph by Edgar Mills The U.S. Navy’s last operational EA-6B Prowler, designed and built by Northrop Grumman, lifts off from Naval Air Station Whidbey Island, Wash. in a ceremonial fly-away June 27 from its long time operational base. The Navy is retiring the Prowler after nearly 45 years of service.   The U.S....
 
 
Air Force photograph by Capt. Tania Bryan

NORTHERN EDGE provides environment for testing new capabilities

Air Force photograph by Capt. Tania Bryan Aircraft from test and evaluation squadrons across the Air Force line up on the Joint Base Elmendorf-Richardson flightline. Northern Edge is Alaska’s premier joint training exercise d...
 




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=""> <s> <strike> <strong>