Evidence for Long Standing Water in Martian Past

[Ursa major]

Water was once widespread on Mars, data from a Nasa spacecraft shows, raising the prospect that the Red Planet could have supported life.

Researchers found evidence of vast lakes, flowing rivers and deltas on early Mars, all of which were potential habitats for microbes.

They also discovered that wet conditions probably persisted for a long time on the Red Planet.

BBC NEWS | Science/Nature | Water 'widespread' on early Mars

[mosaix]

Thanks for this UM.

Mars gets more and more interesting. I just hope they get there in my lifetime.

[Dave]

While extremely likely to be true, I wouldn't say that this research was absolutely conclusive. They are basing their conclusions on the presence of clay minerals in the delta like formations seen on Mars, and saying that clay minerals can only be formed in the presence of water, and deposited in that way under water.

I would say that just looking at some of the Martian pictures myself, there are features there, that as far as we presently know, can ONLY be formed by weathering and by running water. I also agree that, as far as we know, clay minerals can ONLY be formed and deposited like that in the presence of water. However, I don't think we yet know enough about the history of Mars or the weathering processes there to make those conclusions yet. There could be some utterly new chemical processes involved.

We really need an expedition of geologists and geomorphologists and soil scientists to find this out. Apart from the possibility of life, this knowledge could revolutionise our current thinking about the formation of similar minerals and geographical features on Earth.

And if Mars did have so much water, so recently in the past, I find it frightening that it lost it so quickly.

[HardScienceFan]

http://www.earthsci.unimelb.edu.au/m...d_dry_Mars.pdf
http://www.indiana.edu/~geosci/people/faculty/bish/pdf/Vaniman%20et%20al%20sulfates%20on%20Mars.pdf
http://www-mars.lmd.jussieu.fr/grana...ranada2006.pdf
http://oro.open.ac.uk/8230/1/Gullies...igh_Arctic.pdf
http://seismo.berkeley.edu/~manga/gaidos.pdf
http://arxiv.org/ftp/arxiv/papers/0705/0705.3176.pdf

for those interested

[Dave]

Obviously, I didn't read all of those links, but they said similar things to what I did - that there could be another mechanism for the water-like features, such as another solvent - that the Martian climate doesn't seem to have changed, only lost all it's water - that the water might have been the result of volcanic activity melting locked up water deep underground. It is all very interesting, and that last suggestion particularly so.

They also said that the minerals would have to be analysed on Mars itself, as bringing them back to Earth would change them.