Strong evidence of wet past on Mars

(CNN)-PASADENA, California (AP) -- The Mars rover Spirit has uncovered the strongest evidence yet that the planet used to be wetter than previously thought, scientists reported Monday.

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The robot analyzed a patch of soil in Gusev Crater and found it unusually rich in silica. The presence of water would have been necessary to produce such a large silica deposit, scientists said.

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Spirit previously found clues of ancient water in the crater through the presence of sulfur-rich soil, water-altered minerals and explosive volcanism. But the latest find is compelling because of the high silica content, researchers said, raising the possibility that conditions may have been favorable for the emergence of primitive life.

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So if this is evidence that Mars was, or more importantly, is, a ‘wet’ planet then logically, life would have evolved there over billions of years. Evolution which is a natural and universal phenomenon could have resulted in advanced life forms at some stage.

Probably there IS life now on Mars which we have not been able to identify? Keep looking. There may be life out there which if discovered, will undoubtedly have a profound affect on us, turning our scientific and religious templates upside down!

Cheers!

The lack of a magnetic field on mars is probably what prevents life on Mars.

Sorry but i can buy the theory that water once existed there and there may still be remnants in places, but lack of a magnetic field is probably the biggest drawback.

mgs-mager.gsfc.nasa.gov...
* Mars does not presently have a global magnetic field but had one early in its life, similar to that of Earth. However, Mars does have very strong crustal magnetic fields, more than 30 times stronger than those of Earth.
* Developed a detailed map of the magnetic fields of crustal sources.
* The absence of magnetization in large impact basins allowed for the first time to establish the time of cessation of the Martian dynamo, more than 3.5 billion years ago. (Note this is 1.2
* The absence of a global magnetic field for billions of years has contributed to the erosion of Mars atmosphere by the solar wind and the loss of water.

Ya sure these are crustal magnetic fields? They could be where lava still flows! The Martian dynamo may have stopped but the heat inside may still be there somewhere in natural nuclear reactors.
apod.nasa.gov...

I have no philosophocal position in denying life on Mars exists. I would be thrilled if it is found, however I say the evidence of water previously existing on mars is just that.

Whilst some remnant of water will be found, I suggest there was a cataclysmic end to life, the magnetic field and to large bodies of water on Mars.

It ought to warn us here on earth that the consequences of an asteroid strike could well be final extinction of all life on Earth.

Recently released (taken 11/11/06) by the Hi-Rise team on 6/6/07. Suggestive of larger transient surface liquid water flows than previously thought (maybe related to the H2O frost/ice melt in spring??? Gullies seem to suggest a larger amt. than accountable via frost melt though...).

PSP_001552_1410 shows gullies in a crater in Terra Sirenum in the southern hemisphere of Mars.

This image was acquired during the winter, which explains the abundant frost (the bright material) seen throughout the image. The frost is likely water frost, as opposed to carbon dioxide, because temperatures at this latitude probably do not get cold enough for carbon dioxide to condense.

The formation mechanism of gullies is much debated. Several theories support erosion by liquid water, while others favor dry debris flows or carbon dioxide. A major unknown is, if the gullies are formed by liquid water, does the water originate from the surface or subsurface? Dendritic structures, such as those seen in the alcove displayed in the subimage (approximately 1.3 km across; 2560 x 3000, 7MB), form from surface runoff on Earth. Water originating in the subsurface would not produce a structure like this. This alcove is evidence for a surface source for the water possibly required to form gullies.

Also interesting about this scene is the fact that the gullies occur at multiple elevations along the same crater wall. This is uncommon on Mars. Gullies, whether or not they are found in conjunction with an obvious horizontal layer, usually form at the same elevation on a given slope. It is unknown what caused these gullies to form at multiple elevations. Their locations are suggestive of a distributed water source, which also favors a surface, rather than a confined subsurface origin of water, such as an aquifer.

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