NASA Images Suggest Water Still Flows on Mars Options

[Guest_Sunspot_*]

Dec. 4, 2006

Dwayne Brown/Erica Hupp
Headquarters, Washington
202-358-1726/1237

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278

MEDIA ADVISORY: M06-186

NASA SCHEDULES BRIEFING TO ANNOUNCE SIGNIFICANT FIND ON MARS

WASHINGTON - NASA hosts a news briefing at 1 p.m. EST, Wednesday, Dec.
6, to present new science results from the Mars Global Surveyor. The
briefing will take place in the NASA Headquarters auditorium located
at 300 E Street, S.W. in Washington and carried live on NASA
Television and www.nasa.gov.

The agency last week announced the spacecraft's mission may be at its
end. Mars Global Surveyor has served the longest and been the most
productive of any spacecraft ever sent to the red planet. Data
gathered from the mission will continue to be analyzed by scientists.


Panelists include:
- Michael Meyer -- Lead Scientist, Mars Exploration Program, NASA
Headquarters, Washington
- Michael Malin -- President and Chief Scientist, Malin Space Science
Systems, San Diego, Calif.
- Kenneth Edgett -- Scientist, Malin Space Science Systems
- Philip Christensen -- Professor, Arizona State University, Tempe,
Ariz.

[nprev]

Hate to say it, but I think it's gonna be a long time till we can conclusively answer the "L.O.M." question unless we get extremely lucky & identify a completely alien organism in a returned sample. (If hypothetical Martians are biochemically similar to Earth life, it will be much harder to distinguish them from contamination).

If there really isn't any life, it'll take centuries of in situ exploration to reach that conclusion definitively...

[JRehling]

Hate to say it, but I think it's gonna be a long time till we can conclusively answer the "L.O.M." question unless we get extremely lucky & identify a completely alien organism in a returned sample. (If hypothetical Martians are biochemically similar to Earth life, it will be much harder to distinguish them from contamination).

If there really isn't any life, it'll take centuries of in situ exploration to reach that conclusion definitively...

The pessimistic outlook for LOM re: this discovery would be that the same areas on Mars may not be getting anywhere near enough repeat soakings to entail a habitat. There are areas on Earth where various lifeforms lie dormant until flash rains come, but that surely requires some favorable ratio, however slight of wet-to-dry. For example, 10 minutes wet every ten thousand years probably would not do the trick. Mars could be awfully cruel in this way.

My hypothesis on why the sun-facing slopes don't have gullies is that there is a finite subsurface reservoir and the sun-facing slopes already had their gullies and exhausted their supply a long time ago. In essence, I'm positing that the sun-facing slopes are like short-period comets and the sun-hidden slopes are like long-period comets.

[nprev]

The pessimistic outlook for LOM re: this discovery would be that the same areas on Mars may not be getting anywhere near enough repeat soakings to entail a habitat. There are areas on Earth where various lifeforms lie dormant until flash rains come, but that surely requires some favorable ratio, however slight of wet-to-dry.

Re dormancy: If hypothetical Martian bugs can survive extended freeze-drying, then they should have been distributed globally by the wind long ago. Maybe we just need to land an ultra-sterile nutrient solution with an automated microscope pretty much anywhere, toss in some soil, and see what grows...

Even negative results would be most informative. If sporulated bacteria aren't all over the place waiting for water (or dilute H2SO4?) to wake up, then that would set some significant constraints on Mars' biological history--if there ever has been any.

[JRehling]

Re dormancy: If hypothetical Martian bugs can survive extended freeze-drying, then they should have been distributed globally by the wind long ago.

I would have to think it would depend on the numbers. If habitability comes down to a few hectares per minute per year, I think even Good Ol' Durable Life would have a problem spreading enough bugs from one outburst site, spread planetwide, to have a prayer of any of them dropping into another eventual outburst site.

Another problem is that bacteria tend to take time to divide, whereas we haven't seen yet that anyplace would actually be wet for more than minutes. (Or at all, to be a stickler.)

This reminds me of a problem for possible bugs in the clouds of giant planets. There may always be a zone that is wet with comfortable temperatures, but any given bug would get swept down to sterilizing heat in typical situations. In the martian case, the bacteria thriving at one outburst site would have to be so numerous that a tiny fraction of them would land in friendly environments. It's sort of like the math of a nuclear chain-reaction... in reverse.

And of course, airborne dust isn't a great place to hide from UV radiation.

It seems more likely that something would sustain itself locally than to live and travel in the global dustbowl.