Posted on 12/22/2005 10:46:33 AM PST by The_Victor
Why no mention of the atmospheric pressure and temperature on Mars?
The conditions on Mars are average temperature = -63C, pressure = 4-8 millibar (depending on season).
Water is not very fluid at these conditons, if it can exist at all.
The NASA scientists claiming signs of life on MARS have at least the appearance of a conflict of interest for so doing: it is a much better political "selling point" to keep the dollars flowing than if they found no life (which is much less sensational a headline).
According to the theories being put forth, atmospheric pressure there was much higher in the past. Presumably, that would have also meant a more insulative (and therefore warmer) atmosphere.
In fact, one theory I've read about is that Mars was basically a sort of backup hard-drive for life on earth. They say that because the early earth was over 90% covered with water, any impact from the small planetoids flying around the solar system at the time would have vaporized a substantial amount of water and triggered a runaway greenhouse effect, resulting in the entire ocean being turned to vapor and sterilizing the globe.
Mars, on the other hand, would have had much less of its surface covered by water, so while an impact would produce massive local damage, it wouldn't wipe out life globally. So the thinking is, when the water vapor here finally settled out into oceans again, the earth could be re-seeded with life from Mars carried here by impact ejections.
Phase diagram for water:
At 4-8 millibar (1.33 torr/millibar) and -63C you are above the triple point. The scale doesn't give a good indication here, but I think 4 millibar would be in the gas phase, but 8 millibar would be in the liquid.
Ping.
Whoops, you're right -63C would be below the triple point. Need to take more careful note of the sign.
"Instead, the studies argue, the layered rock outcrops probed by NASA's robot rover Opportunity and interpreted as signs of ancient water could have been left by explosive volcanic ash or a meteorite impact eons ago."
Yeah, but when you call them that it doesn't drum up much support for NASA spending.
I appoint you Science Officer of the Starship Freeper.
No life, no news. But maybe RA has some input.
Don't do that. I screwed up the analysis. See post 26
Actually, the failure to find signs of life on Mars would be a great encouragement to the terraforming supporters..
You and I both know, if life forms are found, there will be a veritable flood of environmentalists, that will demand that Mars be "protected" as some intergalactic Wildlife Preserve, and ban drilling for oil, or anything else...
If you wish to terraform Mars, the best thing that could happen is that it be found to be "sterile" and lifeless..
Construction will begin immeadiately after said finding...
That's OK...it's all in the presentation.
The presence of acidic water and sulfur dioxide would not preclude microbial life.
Maybe they should start building cars!
Mars was 'always cold and frozen'The idea that Mars was once a warm place, awash with oceans that could harboured early life has taken a knock - new data suggests it was always cold, frozen and probably lifeless. A survey of the Red Planet's surface has revealed only traces of carbonates, minerals that should have formed in abundant quantities if Mars once had expansive seas. On Earth, the mineral is found in limestone and chalk deposits around the world. The data was collected by a thermal emission spectrometer (TES) on NASA's Mars Global Surveyor and was analysed by researchers at Arizona State University in the US... "We found carbonate, but we've only trace amounts," said team leader Philip Christensen. "This really points to a cold, frozen, icy Mars that has probably always been that way. We believe that the relatively small amounts that we see probably did not come from oceans, but from the [carbon dioxide] atmosphere interacting directly with dust," he said... "We see so much erosion in canyons, and valleys and plains that have been stripped bare," he said. "It seems unlikely that the carbonate rocks could all be hiding out of view. When you look at the entire planet, you'd think that somewhere a little piece would be exposed."
by David Cohen
New Scientist
22 August 2003
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