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Fraser
2005-Jul-22, 03:24 PM
SUMMARY: With the evidence turned up by the Mars Exploration Rovers, the Red Planet was once warm enough to have liquid water flowing on its surface. But according to researchers at MIT that period happened a long time ago; more than 4 billion years ago, in fact. The team analyzed the amount of argon in various Martian meteorites. Since argon known to leak out of rocks at different rates depending on the temperature. they were able to provide this estimate for the age of the Martian deep freeze.

View full article (http://www.universetoday.com/am/publish/so_cool_mars_4_billion_year_freeze.html)

What do you think about this story? Post your comments below.

Greg
2005-Jul-22, 05:25 PM
This is a very good article about some very good research. I have come to believe for a while now that indeed Mars has been cold for the vast majority of its existence (based on other research I have read.) I do not think that from these few samples, however, that this would apply to the whole planet. I think there is every reason to believe that regional warming has happened as a result of geothermal activity and large impacts. Therefore if life had gotten a start in that early warm period, it could have persisted since then in isolated areas. I would look for areas with persistent geothermal activity in order to find it.

Greg
2005-Jul-22, 05:32 PM
On a more biological note, I would like to add how life would persist on Mars if it got started. With abundant water (frozen most of the time) and wind to move things around, any life would have to take advantage of these conditions to survive. Simple organisms would likely evolved spore states allowing them to remain inactive for long periods of time and to be blown around in the wind to new habitats where they should arise (ie new thermal vent opens up somehwere) Consequently, I would expect that such spores would be fairly widely distributed, albeit at very low concentrations, in the soil just about everywhere on the planet. Just some food for thought.

antoniseb
2005-Jul-22, 05:41 PM
Originally posted by Greg@Jul 22 2005, 05:25 PM
I think there is every reason to believe that regional warming has happened as a result of geothermal activity and large impacts.
There are, for example, several geologically recent (Martiologically recent?) volcanos of some considerable size on Mars. There's a chance there was some heat while these things were rising.

TuTone
2005-Jul-22, 08:58 PM
How did Mars once get warm, was it spinning closer to the Sun? How warm was Mars when it was in the "warm" stage?

Guest
2005-Jul-22, 09:17 PM
The estimate on age based on the amount of argon left in meterorites would be accurate maybe if the little darlins were locked up in a climate controlled environment with a temp recorder attached. They are in an open system with who knows what happening to them till we joyously picked em up and declared ourselves knowers of all that has happened and all that will or can happen. :lol:

Mick
2005-Jul-22, 11:46 PM
The only major trouble I have with their research is
1/ How long was the meteorite ALH84001 in space after being blasted off Mars before it landed on Earth
2/ We have no way of knowing where in Mars this piece comes from

Without knowing this shouldn't they have said this meteorite has been cold for 4 billion years

aeolus
2005-Jul-23, 04:33 PM
Originally posted by Mick@Jul 22 2005, 11:46 PM
The only major trouble I have with their research is
1/ How long was the meteorite ALH84001 in space after being blasted off Mars before it landed on Earth
2/ We have no way of knowing where in Mars this piece comes from


They actually can determine how long the meteorite was in space for. While it is on either planet, it is sheilded by atmosphere and/or magnetic field. In space, though, there is no such protection, allowing cosmic particles to saturate into the meteorite. Using a simple analysis of rates and counts of cosmic radiation, we can figure out how long it was in space between being blasted off Mars and falling down to Earth.

alfchemist
2005-Jul-24, 10:00 AM
This is article is quite disappointing! The prospect of life on mars being narrowed down. Are the rovers on the martian surface capable of gathering similar data on rocks on martian surface?

Nereid
2005-Jul-27, 09:51 PM
Originally posted by TuTone@Jul 22 2005, 08:58 PM
How did Mars once get warm, was it spinning closer to the Sun? How warm was Mars when it was in the "warm" stage?
It had a much denser atmosphere, capable of retaining heat much the same way the Earth's can.

That's the big question! :P No one knows yet; perhaps it was a global average of 0C, or maybe 20C; anyway, the temperature may well have been high enough, and the pressure too, for the 'triple point of water (http://en.wikipedia.org/wiki/Triple_point)' to have been around in the atmosphere (and on the ground?), at least in places.

Nereid
2005-Jul-27, 09:54 PM
Originally posted by alfchemist@Jul 24 2005, 10:00 AM
This is article is quite disappointing! The prospect of life on mars being narrowed down. Are the rovers on the martian surface capable of gathering similar data on rocks on martian surface?
No.