[X] My Assistant

[mhoward]

Bunch of MI's of the "rind" (mentioned in Steve Squyres' latest mission update), I believe, starting with this one:

http://nasa.exploratorium.edu/mars/opportu...DIP2956M2M1.JPG

Forward hazcam:

http://nasa.exploratorium.edu/mars/opportu...DIP1110L0M1.JPG

[mike]

I wager that Mars has had a more interesting history than anyone has necessarily imagined thus far.. Perhaps it was Earth, just a few billion years earlier and terminated before it had space-faring beasties. Then again, maybe it had space-faring beasties, and all their Earth-sent probes have since been obliterated. Earth would have been rather uninteresting compared to Mars back then.

How about this, Earth was going along pretty well, then whatever gave us the Moon hit Earth, and voila, set us back a few hundred million years or so. Mars on the other hand keeps cranking, and hey, Deimos and Phobos aren't huge, but neither is Mars, so surely they would induce some sort of decent tidal effects (thought to be important to the formation of life on Earth, by me if no one else). But then, the sun cools down, Mars' lower gravity isn't enough, and it all disappears, or freezes onto the surface, or both, and next comes Earth.

As the sun cools down further (before going red giant..), I imagine Earth's climate will change quite noticeably and Venus will cool down etc. etc. etc.

And if I'm wrong about the current ideas of star formation (perhaps stars start cold and get hotter and hotter until they go red giant, eh?), then guess what, THEY'RE ALL WRONG. But in that case I'll couch my bets and just say that Venus was once Earth and Mars will be Earth soon enough. Except that we don't have any probes on Venus (yet) so I don't find that as exciting right now.

Once we find those ancient Martian tools a few feet beneath the surface, you'll all know I was right.

[RedSky]

As the sun cools down further (before going red giant..), I imagine Earth's climate will change quite noticeably and Venus will cool down etc. etc. etc.

Actually, I think the current thinking on main sequence stellar evolution is that the sun is expected to increase slowly... but continuously, in luminosity over the next few billion years. In fact, the earth would probably become uninhabitable due to this effect long before the sun reaches the red giant stage. (I think it has to do with the fact that the hydrogen "burning" keeps progressing out in a layer from the center... which becomes too helium-rich for efficient nuclear fusion).