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Mars Had Surface Water for Eons
LukePieStalker writes "Far from being a one-time event, it now appears that surface water
flowed on Mars for eons. Nasa has announced that, after descending
down further into the Endurance crater, the Opportunity rover has found a 'razorback'. It is believed that this was formed by 'fracture fill' from the minerals in percolating water. Since this feature extends through several geologic layers, it argues for a long period of wetness near the surface. This would seem to substantially increase the chance that life once existed on the red planet."
Is water all that common?
Not only is water uncommon, the liquid phase is uncommon. Also, the reason it's so important is because it is less dense in the solid phase than the liquid phase, which allows it to freeze on top instead of on bottom, which in turn allows organisms to sustain life even when the body of water begins to freeze.
I are winner
Water should be pretty common near stars as Hydrogen is the fuel which runs them. When combined with oxygen pulled near the star by gravitation, you find yourself with water. The difficulty is in finding it in liquid form. Planets and planetoids near a star will have their water blown or boiled away. This water will then travel toward the outer system. If no large body exists in the star's "temperate zone", then the water will continue on. If it hits a body outside of the "temperate zone", it will remain as ice.
At least, that's how I understand it.
Javascript + Nintendo DSi = DSiCade
We know there's still water there; unfortunately, it's in the form of ice.
As for fossils or traces of life... who knows? All we can say is that Spirit and Opportunity aren't going to be finding it unless it's macroscopic. They can only dig centimeters deep, and don't have the sort of magnification needed to see microscopic organisms.
Windmills do not work that way!
"Not only is water uncommon, the liquid phase is uncommon"
That should have read:
"Water is not uncommon; only the liquid phase is."
Our solar system is jam packed full of ice. Heck, Uranus and Neptune are best described as "Ice Giants" instead of "Gas Giants", due to their expected ice cores. Ice dominates the moons in the saturnian system, the kupier belt and oort clouds are composed mostly of ice, etc, etc. In fact, it is even theorized that Earth got its water from comets.
Windmills do not work that way!
Erm, minor correction: Uranus and Neptune have ice mantles, not cores. Their cores are expected to be rock. Their atmospheres are relatively thin compared to the true "Gas Giants".
Windmills do not work that way!
Both Mars and Venus are bone dry because they have little to no magnetosphere. This allows water vapor to be broken into H and O by UV radiation and since the H is light, it can acheive escape velocity much faster when hit by unhindered solar wind.
Blaze a trail to the New World
Earth has a large moon which stabilizes the tilt angle of its rotation axis. The Earth bulges at at equator from its rotation and the pull of the moon. The moon pulling on this bulge keeps the earth's axis steepening much more than it is now- a 23-degree tilt. The tilt angle creates the seasons. If it tilted more, there'd be warmer summers and colder winters.
Mars lacks a significant moon. Therefore people speculate that it could tilt all the way over on its side sometimes and have extreme seasons. Maybe even extreme enough to melt the carbon and water ices at the poles and permafrost.
They already did that on Viking. The results were inconclusive, but suggestive of abiotic processes. The tests were as follows:
GEX (Gas EXchange experiment): Looked at gas level changes in martian soil vs. a control which it sterilized first.
LR (Labeled Release experiment): Looked for uptake of a radioactive liquid by gas presence, again vs. a control which it sterilized first
PR (Pyrolytic Release experiment): Like the LR, but in reverse; cooked the samples afterwards to see if they uptook radioactively tagged CO2.
GCMR (Gas Chromatograph - Mass spectRometer experiment): Heated soil samples and did a spectral analysis of them.
First, GCMR's results: Found an unexpected amount of ice, but found surprisingly *little* organics, leading scientists to conclude that some process was *destroying* organics on Mars.
For the others, the following would have been expected from each if there was life:
GEX, sample: O2 or CO2 released
GEX, control: No release
LR, sample: Labelled gas emitted
LR, control: No release
PR, sample: Carbon detected
PR, control: None
If there was no life, both samples and controls were expected to be the same. The real results?
GEX, sample: O2 released
GEX, control: O2 released
LR, sample: Labelled gas emitted
LR, control: No release
PR, sample: Carbon detected
PR, control: Carbon detected
In short, it was confusing, but was believed to be related to abiotic processes.
Windmills do not work that way!