Ancient Mars

[Dollan]

Has anyone done, or does anyone know of, a texture for Mars with surface water. I don't mean a terraformed Mars, but rather what the planet may have been like some 3 billion years ago or so?

...John...

[Evil Dr Ganymede]

I'm guessing it'd look similar to how it looks now (any water notwithstanding), with a few less impact craters. The Tharsis bulge might still be forming around then though, so the volcanoes there should still be active (assuming they've formed yet).

[Don. Edwards]

I made one and will have a new 16k version available on the Mars Central site soon.
BTW it is called Mars 3-Billion-BCE.

Don. Edwards

[Dollan]

Wonderful! I'll ask now if it would be okay to use it as a thumbnail for a planet type on my PCL page? As usual, it would have all the usual copyright info and contact info for you.

...John...

I made one and will have a new 16k version available on the Mars Central site soon.
BTW it is called Mars 3-Billion-BCE.

Don. Edwards

[Don. Edwards]

Dollan,
You will find a small thumbnail of the Mars 3 billion BCE texture on my Mars Hub site.
http://www.celestiaproject.net/~impulse/Mars_C ... ntral.html
Hope this gives you an idea of were the texture is going. The thunbnail may look a little dark.

Don. Edwards

[Dollan]

Hi Don...

Just some random thoughts about an ancient Mars...

As was mentioned, there would likely be far less impact craters, or at least more sharply defined craters in the southern lands. Valles Marineris might be somewhat smaller, and possibly marked by visible occurances of volcanism (thinking of an over-sized rift valley, here). Martian volcaoes would be pretty active, and Olympus Mons itself might be brightly lit on the night side.

Clouds would be thicker, probably eual to Earth now, although their composition might be rich in primordial methane as well as CO-2. It is possible, of course, that Mars would have been completely swathed in a dull orange cloud cover, as ancient Earth may have been.

Anyway, I don't know if this helps at all; I'm sure you have your own plan of attack anyway!

...John...

[Evil Dr Ganymede]

Hope this gives you an idea of were the texture is going. The thunbnail may look a little dark.

Maybe it's because the thumbail is small, but I can't actually see any difference between that and Mars today other than it's has dark brown lowlands... can you point out the differences?

[Guest]

As I understand it, the Hellas impact crater formed after the end of the Noachian period, and after the Martian magnetic field disappeared. This is shown by the lack of fossil magnetism in that crater.

So that crater should not be there; the same may be true of Argyre, but I am not certain.

[eburacum45]

Logs in to claim last message-
after having checked a few sources on Martian geology, it seems that the Martian magnetic field did not last very long; so the Hellas crater was probably there at 3 billion bpe after all; it seems to predate the Tharsis bulge, anyway.

[Dollan]

Hey Steve...

Interesting. Tonight I may have to do a little research. I wonder what kind of effects the Hellas impact would have had, then, that early. I would bet that, if there were indeed sizable seas and oceans on Mars, it would have sported either a roiling body of water (assuming that the crater interior punched deep enough to release magma ala the Moon's maria), or that it would have been a dry, possibly volcanic hell-zone....

...John...

[Don. Edwards]

From a few things I have read the Helas impact was the cause of the Tharsis rise in the first place. When the asteroid/comet hit the Earth 65 million years ago on the opposite side of the Earth the impact shock waves were focused on India as it happen to be in this location at that time and this caused the crust to break and vast amounts of magma erupted to the surface. It is believed that the same thing happened to Mars. The shock waves of the impact focused fractured the crust on the opposite side of Mars in what would become Tharsis and magma came to the surface. The result was the Tharsis rise and its volcanoes. The same thing goes for the Argyre impact. If you look at Argyre and then look on the opposite side what will find? The Alysium rise and its volcanoes. I think this pretty much helps support this theory.
As for Valles Marineris it is not conclusive that it is in fact a rift valley. There are no signs of any kind of volcanism in its floor or around it sides. If you look at the rift valleys under the oceans of Earth or the rift valleys of Africa there are volcanoes all along there side and down in the rift valleys themselves. There is some evidence that some parts of the valley system may be formed from the collapse of aquifers under the surface. This would explain the vast amounts of water that has obviously flowed out from the system in the past. If you think in a geologist mind set and look closely at Mars surface features these things start to make some sense.
Now as for the atmosphere at this time. I don't think it would have been like Earth's at this time. Yes there would have been clouds much like we see on Earth today but we wouldn't see an atmosphere like Venus' per say. Mars is smaller and went through a faster cooling process due to its smaller size and distance from the sun. Putting all though factors together is how I am making the texture. Also they are constantly changing there estimates of what happen and when on Mars. So there is some room for interpretation at this time or until I can be proven completely wrong. And at this time I think it is going to be a while till we know every bit of Mars history. I will post some pictures of how the texture looks at this time and then you can give me input as were to go.
Evil Dr Ganymede,
Those dark valleys are not valleys but seas and oceans!

Don. Edwards