Posted on 06/20/2008 6:40:51 PM PDT by rarestia
What more do we know about Mars' atmosphere? It's hundreds of times thinner than Earth's atmosphere and is made of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and contains traces of oxygen, water, and methane. We also know, from observations that it can support dust storms, dust devils, clouds and gusty winds. With an amazing number of six current live probes exploring Mars (two rovers, a lander, and three orbiters), there are many thousands of images available. Only a few, however show atmospheric phenomena. Presented here are some of the best images of Martian atmosphere (and beyond) in action. (17 photos total)
(Excerpt) Read more at boston.com ...
Wouldn’t frozen CO2 (dry ice) also disappear though? Do we know it was WATER ice and not dry ice?
Per the NASA press release today, it’s not cold enough for dry ice to last as long as this ice did:
http://phoenix.lpl.arizona.edu/06_20_pr.php
“The key new evidence is that chunks of bright material exposed by digging on June 15 and still present on June 16 had vaporized by June 19. “This tells us we’ve got water ice within reach of the arm, which means we can continue this investigation with the tools we brought with us,” said Mark Lemmon of Texas A&M University, College Station, lead scientist for Phoenix’s Surface Stereo Imager camera. He said the disappearing chunks could not have been carbon-dioxide ice at the local temperatures because that material would not have been stable for even one day as a solid.”
Why does that second picture make me want to say “Danger Danger Warning Will Robinson?”
Yes, ice on an otherwise frozen part of a somewhat frozen planet could get me all excited too … not. Now, footprints in that Ice might get my attention. ;-)
“Today will see a high temperature of a toasty -26 degrees F.”
What I have been wondering is if the high temperature is only reachidng -26 degrees F how did the ice melt. Does not the 32 degree F still hold?
Same question asked on the NASA photo blog. The answer is that the air temperature in the Martian summer (which is now) is much too high for solid CO2 to exist---it has long already vaporized--so what is left pretty much HAS to be water ice.
The water ice goes directly from a solid to a gas without melting to a liquid. It can happen to a small extent on earth. Its like what happens to dry ice in our atmosphere.
No, it doesn’t. Because the Martian atmosphere is so thin, the boiling point of water there is 4degrees Celcius.
I just stared at the picture of Earth and our Moon for about 10 minutes. Wow, just wow.
If there were some way to get the water into the atmosphere to trap more heat, with all that CO2, we could plant some kind of green vegetation and viola - oxygen and atmosphere!
Terraforming is possible, scientifically. It’s the logistics and brute force needed that makes it hard - we need so much more atmosphere than what’s there.
We know there’s water but not how much. We also need more CO2 to make enough oxygen.
I do think someday, maybe 300 years from now, it will be done.
We would also need to find a means of setting up a massive magnetic field around the planet.
New planet = new science?
I had the same reaction as many, though, wondering why this couldn't be dry ice ( on mars, that is. ) Sublimation rates are very tricky, and you can find a lot of abstracts on the internet for papers about sublimation rates under various conditions.
I suppose these guys are right, but I have yet to find anything that tells me water ice would sublimate this fast under these conditions. This stuff is covered by only a few centimeters of soil, so how could it last indefinitely with such a thin covering and yet disappear in less than 4 days on the surface, ( apparently not even exposed to sunlight, from the picture? )
How could it look so much like salt, that they would consider that it might be salt? Water ice becomes very strong and hard at low temperatures, and I wonder about that. How could they fail to detect even a trace of water in the overlying thin layer of soil? ( They already announced this. )
Also, I see a model proposed for a permanent CO2 Layer over a deeper water ice mantle. This is for the south pole, but the idea proposed is consistent with CO2 "hummocks" like the one Phoenix is digging on.
So, I remain skeptical in my own mind, even though I'm in no position to argue with the experts, but if they dump this stuff in their TEGA, and don't get a monster H2O signal, they'll have some 'splainin' to do.
in the low pressure of the Martian atmosphere, the ice will sublimate
my favorite as well
What is the pressure dependency of the sublimation rate? If you know, tell me, because I can’t find it on the internet.
Good heavens. That’s my new desktop. Incredible.
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