NASA Briefing: NASA Images Suggest Water Still Flows in Brief Spurts on Mars

NASA ^ | 6 December 2006

[bd476]

NASA Images Suggest Water Still Flows in Brief Spurts on Mars

12.06.06

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NASA photographs have revealed bright new deposits seen in two gullies on Mars that suggest water carried sediment through them sometime during the past seven years.

" These observations give the strongest evidence to date that water still flows occasionally on the surface of Mars," said Michael Meyer, lead scientist for NASA's Mars Exploration Program, Washington.

Image right: A new gully deposit in a crater in the Centauri Montes Region. Image credit: NASA/JPL/Malin Space Science Systems
+ Full image and caption

Liquid water, as opposed to the water ice and water vapor known to exist at Mars, is considered necessary for life. The new findings heighten intrigue about the potential for microbial life on Mars. The Mars Orbiter Camera on NASA's Mars Global Surveyor provided the new evidence of the deposits in images taken in 2004 and 2005.

"The shapes of these deposits are what you would expect to see if the material were carried by flowing water," said Michael Malin of Malin Space Science Systems, San Diego. "They have finger-like branches at the downhill end and easily diverted around small obstacles." Malin is principal investigator for the camera and lead author of a report about the findings published in the journal Science.

The atmosphere of Mars is so thin and the temperature so cold that liquid water cannot persist at the surface. It would rapidly evaporate or freeze. Researchers propose that water could remain liquid long enough, after breaking out from an underground source, to carry debris downslope before totally freezing. The two fresh deposits are each several hundred meters or yards long.

Image left: A new gully deposit in a crater in Terra Sirenum. Image credit: NASA/JPL/Malin Space Science Systems

The light tone of the deposits could be from surface frost continuously replenished by ice within the body of the deposit. Another possibility is a salty crust, which would be a sign of water's effects in concentrating the salts. If the deposits had resulted from dry dust slipping down the slope, they would likely be dark, based on the dark tones of dust freshly disturbed by rover tracks, dust devils and fresh craters on Mars.

Mars Global Surveyor has discovered tens of thousands of gullies on slopes inside craters and other depressions on Mars. Most gullies are at latitudes of 30 degrees or higher. Malin and his team first reported the discovery of the gullies in 2000. To look for changes that might indicate present-day flow of water, his camera team repeatedly imaged hundreds of the sites. One pair of images showed a gully that appeared after mid-2002. That site was on a sand dune, and the gully-cutting process was interpreted as a dry flow of sand.

Image right: A colorized view of a new crater on the upper north flank of the Martian volcano Ulysses Patera. Image credit: NASA/JPL/Malin Space Science Systems

Today's announcement is the first to reveal newly deposited material apparently carried by fluids after earlier imaging of the same gullies. The two sites are inside craters in the Terra Sirenum and the Centauri Montes regions of southern Mars.

"These fresh deposits suggest that at some places and times on present-day Mars, liquid water is emerging from beneath the ground and briefly flowing down the slopes. This possibility raises questions about how the water would stay melted below ground, how widespread it might be, and whether there's a below-ground wet habitat conducive to life. Future missions may provide the answers," said Malin.

Besides looking for changes in gullies, the orbiter's camera team assessed the rate at which new impact craters appear. The camera photographed approximately 98 percent of Mars in 1999 and approximately 30 percent of the planet was photographed again in 2006. The newer images show 20 fresh impact craters, ranging in diameter from 7 feet (2 meters) to 486 feet (148 meters) that were not present approximately seven years earlier. These results have important implications for determining the ages of features on the surface of Mars. These results also approximately match predictions and imply that Martian terrain with few craters is truly young.

Mars Global Surveyor began orbiting Mars in 1997. The spacecraft is responsible for many important discoveries. NASA has not heard from the spacecraft since early November. Attempts to contact it continue. Its unprecedented longevity has allowed monitoring Mars for over several years past its projected lifetime.

NASA's Jet Propulsion Laboratory, Pasadena, manages the Mars Global Surveyor mission for the NASA Science Mission Directorate, Washington.

[kinsman redeemer]

I must emphasize: my "HUMBLE" opinion.

I have some experience with geology - a little more with photo interpretation. Put these tow together and you get a very limited understanding - just a perception. That's all.

[epluribus_2]

couldn't it just be an impact from a (big) iceball that melted then evaporated?

[epluribus_2]

martians irrigate with a redder substance, IIRC from WOTW.

[kinsman redeemer]

It appears to be on a steep slope. It appears to be in a crater. I am just guessing here.

Furthermore, - if water: then why is the pattern more of a delta ?- downslope, I would expect to see confluence of the tributaries. I see the opposite.

I think NASA wants (needs?) something spectacular and stimulating.

[brownsfan]

"They farm out programs to universities and aerospace companies, which is where biologists might be found."

It seems to me that employing a large number of biologists at NASA would be like having your African Safari guide meet you at your home in the US.
You have to get there, and then have something of interest before a biologist becomes key. Sure, they could help you refine your search, but if you don't have the hardware/systems people, there is no search. First things first. NASA is a punching bag lately, I see no reason to beat them up over such a point.

[kinsman redeemer]

It could have been a "small" impact that initiated the slide. Otherwise you might see some ejecta from the impact.

Maybe.

[Unmarked Package]

"IMHO - you are looking at a slide on a talus slope. Nada mas."

They discussed this possibility at length in response to a question by a reporter from the New York Times. In summary, they conclude it's not likely to be a dry slide because; 1) previous observations of disturbed or displaced surface material on Mars invariably produce regions darker than the surrounding area, and 2) dynamic analysis of the structure of the flow strongly indicate a fluid was involved in the process.

[Raymann]

I don't think so, if it were unoxidized iron that would mean the earth on top was pretty compact. If it slid down then it would not have crumbled like that to form those splinter streams. The slope isn't that steep, the material would have to be the consistency of sand or less to flow like that.

[bd476]

RightWhale wrote: "We could probably dig that number out of Google. There are very few. Most NASA staff would be hardware or system management and scientists. Scientists would be astronomers and geologists, maybe a few biologists. NASA itself has about 30,000 on staff. They farm out programs to universities and aerospace companies, which is where biologists might be found."

RightWhale, without a numerical breakdown on the occupations of all of NASA's employee roster including the number of

• geologists,
• astrophysicists,
• design engineers,
• mechanical engineers,
• astronomers,
• computer techs,
• computer programmers,
• astronauts,
• astronauts in training,
• physicians,
• electrical engineers,
• physicists,
• mechanics,
• research and development staff,
• administrative staff,
• clerical staff,
• security,
• media relations staff and
• other support staff, etc.

it becomes extremely difficult to make a judgment call that NASA is deplete in one or another field of expertise or occupation.

[kinsman redeemer]

Thank you. I am not convinced by the "we never saw that kind of color change" argument - alone. We are learning more all the time.

What is "dynamic analysis of the structure of the flow?" If that means the dynamics of flow and the resulting structure - then I'd ask, "Why does it appear to be a distributary on a downhill slope? " It doesn't appear to reach a flat area - atleast not from a monoscopic view of the image.

Please - I am only speculating here - I hope you understand.

[Rutles4Ever]

According to the media:

Proof of life

Not proof of life...

[Defiant]

Are they sure this isn't a closeup of the inside of Robert Byrd's mouth? Sure looks like his teeth and gums.

[SengirV]

Well done

[verum ago]

IMHO - you are looking at a slide on a talus slope. Nada mas. Unexposed material is now exposed; it is unweathered and unoxidized and brighter in appearance. It is probably high in iron.

I'm not going to pretend to know much about geology, but (a few IMHO's here) Mar's atmosphere is primarily CO2-- there should be essentially no oxidation taking place, meaning that the inside and outside of rocks and and the tope layer and inner body of a talus slope should be basically chemically identical (and therefore the same color). Also, the article notes that the tracks left by the Rovers, whirlwinds, and the interiors and ejecta of new craters have all been pretty consistently darker than the surounding, undisturbed material.

[kinsman redeemer]

BEST post I have ever seen!

That is the best observation I have seen on the subject.

THANKS - VERY much!

[dfwgator]

How long until somebody is selling Martian water on EBay?

[steve86]

I agree -- Post Hall of Fame. I just logged in to concur!

[kinsman redeemer]

Okay, then.

I give up. Being overwhelmed by facts and opinions of professionals, it is good to resign one's fallacious position and learn from the experience.

[RightWhale]

NASA does have some biologists on staff. For one thing, there is considerable work to be done developing spacecraft that will support life. Sometimes they get life in there that they don't want or need such as the stuff that was eating porthole glass in the Mir. Biologists work on that, too. They will need to learn how to grow food on the moon and on Mars and maybe on their spacecraft. Biologists, again.

[bd476]

kinsman redeemer wrote: "I must emphasize: my "HUMBLE" opinion.

I have some experience with geology - a little more with photo interpretation. Put these two together and you get a very limited understanding - just a perception. That's all."

That's valid, Kinsman Redeemer. Personally I like to hear people's opinions, even from those with little to no experience, because often the simplest question, theory or disagreement can lead to a better answer.

Sometimes it can be difficult to accept photos and scientists' interpretations of photos as absolute evidence just for the simple fact that scientists have been known to make mistakes.

Further, no question should be considered a dumb question. Questions can lead to contemplation, perhaps more study and possibly a new answer.