Signs of water on the Red Planet to spark debate as to whether or not to send a robotic craft to look for life. By Leonard David Senior Space Writer posted: 07:48 am ET 21 June 2000 ET
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WASHINGTON -- The prospect that NASA's Mars Global Surveyor has detected signs of water at a specific site on the Red Planet is likely to spark debate as to whether or not to send a robotic craft on location to look for life.
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But the spotting of water on Mars could alter NASA decision making.
"As far as I'm concerned, if there's solid evidence for the possibility of water, that would probably put that site to the top of everybody's list," said Penny Boston, a biologist who heads Complex Systems Research, Inc. in Longmont, Colorado.
"This would be fabulously exciting. It would knock my little socks off to hear about water," Boston said.
SPACE.com reached Boston June 21 at the University of Valencia in Valencia, Spain. She is attending the Chapman Conference on the Gaia Hypothesis, and is a co-convenor of the program that focuses, in part, on biospheres evolving on other worlds, such as Mars.
"The only way we can approach this problem of life on other planets, at this point, is to really use ourselves as a model, in the broader sense. We can't imagine very well how to do life with our kind of chemistry without water. So the access to water is pretty key," Boston said.
Even if Mars is found to be rife with water but without living organisms, Boston said, it still might be a place where fossil or other traces of past life might exist.
Biological show-stopper?
Locating water on Mars should short-circuit a decision to fly another orbiter mission in 2003, Boston said. Rather, the need for quick examination of a water-rich site would demand on-the-ground confirmation, she said.
"So you would need some kind of landing instrument, or a suite of landing instruments," Boston said.
But there is a show-stopper.
At the insistence of many biologists, Boston said, there is likely to be a call for
planetary protection. "If there were some active water source, then the possibility of contaminating that by spacecraft is much more serious than landing on the dry surface," she said.
The notion of barnstorming into the location with space hardware should be curtailed quickly, Boston said. "We would have to rethink a lot of the planetary protection protocols, I believe, if water is present there. Because then we would be dealing with a possible, highly biologically sensitive site," she said.
Precision landing? Precisely the point
Targeting a
robot lander to a select patch of Martian turf is a tough assignment, said Carol Stoker, a NASA researcher who tests planetary rovers at the space agency's Ames Research Center at Moffett Field, California.
"It depends on where this purported water is. We can't accurately land some places right now, not without really improving entry and landing technologies, which remains important to do," Stoker said.
Stoker said that a water-laden zone on Mars might be very, very small.
Therefore, pinpoint landing of equipment, such as a rover capable of driving over to the location, would be mandatory, she said.
But a real limitation still facing planetary rovers is just how far, how fast, and for how long can they travel. Stop-and-start operations of a rover, controlled from Earth, is time consuming, Stoker said.
"Right now, how far you can safely move a rover, given the level of autonomy now available or planned for rovers, is not very good," Stoker said.
NASA not the only show in town
The first lander that might have a chance to check into the water mystery could be a British Mars lander called the
With NASA's Mars program in disarray, the Beagle 2 is the only spacecraft currently scheduled and approved to land on Mars. It will carry a suite of instruments to test the planet's land and atmosphere.
But even if undeniable evidence is presented of standing water in a Martian crater, the craft isn't necessarily capable of going to it, said the project's lead scientist, Colin Pillinger. Rumors have indicated that the crater showing possible signs of water is small, on the order of 18 miles (30 kilometers) across, and relatively far south.
"That is too small for us to be able to target with our landing system. Our entry-descent-and-landing system is geared up for going to places which are close to the equator," he said. Getting into a crater, or other deep feature to get at the lowlands where water might lie would also be difficult, said Pillinger, a planetary scientist at the Open University near London.
"Now that isn't to say that if we wanted to have a crack at Valles Marineris, we couldn't, but it's a high-risk strategy. It's not the sort of place that one would want to aim at if this was your only effort at landing." The grandest canyon on Mars, Valles Marineris, is more than 2,500 miles (4000 kilometers) long, and varies in depth from 1.2 miles (2 kilometers) to 4.3 miles (7 kilometers).
"It's not to say that we wouldn't discuss it, but we'd have to think very very carefully and hard about this," Pillinger said.
The mere prospect of actually having a detection of water on Mars is tremendously exciting, Pillinger said. "Everybody is aware that there have been huge quantities of water on Mars in the past and people have speculated ad infinitum about where it's all gone to and where it might be. And its great that somebody thinks they might have some evidence of seeing some."
Huge news
It's too early to speculate what the ultimate fallout from any water-on-Mars announcement might be, NASA's Stoker said.
"It's possible that it will push a particular mission approach. Perhaps it might bring sample return back to the fore. Or it might bring rovers, or landers back to the fore. It might drive Mars planners to really bite the bullet and give us pinpoint landing accuracy early...or it may not. Right now, it's hard to say," Stoker said.
For biologist, Penny Boston, water on Mars would be "huge news," she said. "It's something that, of course, we've been looking for on Mars some 30 years now. It's a key to a whole lot of sciences, particularly the life sciences," she said.
Boston said that following the water on Mars might result in a more daring NASA.
"So a site that might have been considered too risky to land, if it had the promise of great payback, like confirmation of water, would sway the agency to be a little bit more daring in what they were willing to do in terms of landing site," Boston said.
SPACE.com staff writer Greg Clark contributed to this report.
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