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View Full Version : Mars mystery solved? (don't mean aliens)



Effendi
2006-Aug-17, 06:08 PM
Could you please look at this article?
http://www.space.com/scienceastronomy/060816_mars_icecaps.html

From what I understand, and not all do I understand (English scientific terminology), this means that Mars is not emerging from any Ice Age, as previously suggested. There is no ice caps melting. Right? Or did I get it all wrong.

Blue Fire
2006-Aug-17, 07:39 PM
Could you please look at this article?
http://www.space.com/scienceastronomy/060816_mars_icecaps.html

From what I understand, and not all do I understand (English scientific terminology), this means that Mars is not emerging from any Ice Age, as previously suggested. There is no ice caps melting. Right? Or did I get it all wrong.
I'm not sure it directly addresses Mars emerging from any Ice Age or not, but I would have to agree that the observed carbon dioxide jets do clearly imply a different reason for the reflectivity change other than melting ice in the southern ice cap. It does say that it's a seasonal, repetitive phenomenon but doesn't directly state whether there is a net and permanent change in the amount of polar ice.

01101001
2006-Aug-17, 07:47 PM
From what I understand, and not all do I understand (English scientific terminology), this means that Mars is not emerging from any Ice Age, as previously suggested. There is no ice caps melting. Right?
I'm not sure I see a conflict between the recent understanding that carbon dioxide jets result in dark patches on the polar ice(s) and Mars' emerging from an ice age.

From the NASA press release of December 2003, Mars May Be Emerging From An Ice Age (http://www.nasa.gov/home/hqnews/2003/dec/HQ_03415_ice_age.html), it doesn't appear to me that the conclusion came from seeing the dark spots in polar regions and assuming that they were the result of melting that was revealing the land beneath.


Discoveries on Mars, since 1999, of relatively recent water-carved gullies, glacier-like flows, regional buried ice and possible snow packs created excitement among scientists who study Earth and other planets. Information from the Mars Global Surveyor and Odyssey missions provided more evidence of an icy recent past.
[...]
They concluded a covering of water ice mixed with dust mantled the surface of Mars to latitudes as low as 30 degrees, and is degrading and retreating. By observing the small number of impact craters in those features and by backtracking the known patterns of changes in Mars' orbit and tilt, they estimated the most recent ice age occurred just 400 thousand to 2.1 million years ago, very recent in geological terms.
The evidence appears more to be a variety of old effects left behind a retreat of the ice, not observations of ice retreating in the very short term.

The closing section of the Space.com article, labeled Unclear Slab of Ice, might conflict more with the idea of a retreat, but it's unclear (heh). If the lack of impact craters in ice-free areas turns out to be a lack of craters in dust-covered ice, then perhaps there could be problems. There's not enough meat in the article though to determine if these areas are the same ones studied by the ice-age-ending folks, and I don't subscribe to Nature to read more.

Effendi
2006-Aug-17, 09:30 PM
Is there any correlation between Ice Ages on Mars and on Earth? Those statements don't seem to support that, do they?:

By observing the small number of impact craters in those features and by backtracking the known patterns of changes in Mars' orbit and tilt, they estimated the most recent ice age occurred just 400 thousand to 2.1 million years ago, very recent in geological terms.