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Maps Show Mars Was Once More Like Earth
vrioux writes "NASA scientists have discovered additional evidence that Mars once underwent plate tectonics, slow movement of the planet's crust, like the present-day Earth. A new map of Mars' magnetic field made by the Mars Global Surveyor spacecraft reveals a world whose history was shaped by great crustal plates being pulled apart or smashed together. ."
I *think* I recall hearing that one of the reasons Mars could not "keep it together" the way the Earth did is because the core may have a different atomic/elemental makeup.
Any planetary scientists that can attest to/debunk this?
We behave a lot more like the animals on Earth than we behave like all the animals we know of on Mars. (I.e. none)
Besides, what's with this "exactly" requirement anyhow? No two animals (or people, if you think we mustn't be counted as animals) behave exactly like each other either. Maybe we all come from different planets! There's a planet somewhere that's full of exact copies of me!
(And there's a world filled with nothing but shrimp. I grew tired of that world quickly.)
Or (like the other poster said), maybe we come from Pak. That's a hell of a lot more likely than that Adam and Eve came from Mars.
Incidentally, the impactor blew that crustal material clear into orbit, which ultimately coalesced into the moon. See the giant impact theory entry on Wikipedia.
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This is a fairly common theory (especially in the wake of the early findings that the other planets in the Solar System are uninhabitable by humans), but our studies of our own solar system suggest it to be untrue. If life were as adaptable as suggested, then we'd find inflatable beings on Jupiter, Crystaline entities on Venus, creepy crawlers on Mars, and other life forms well suited to their environment.
Yet no such creatures have ever been found. Hope is still held that water creatures may be found on Jupiter's Icy Moons (specifically Europa), but we've pretty much exhausted the remainder of the Solar System.
I'm going to have to argue with that. To be perfectly honest with ourselves, we can't say whether life only exists on a physical plane, or a mixture of magnetic, physical, spritual, gaseous.. we have no idea. It could be that life is abundant in forms we just haven't had the opportunity (capability) to discover yet. When one looks at areas that now seem unihabited, it seems impossible that they ever were. At present, desert covers a large part of Australia, The Great Sandy Desert, The Gibson Desert and the Great Victoria Desert combine to fill more than half of Western Australia. It was covered by large sheets of ice before that, and before that by a shallow ocean, which was most defintely teeming with life. The south pole has produced palm tree fossils. To a temporary observer (as we are to the celestial bodies), the south pole seems dead. it was once covered in life. Things change, things move, and accidents happen. Just because our sister and brother planets look devoid of life now, doesn't mean they are or have been. Or will be for that matter.
** "It's not my job to stand between the people talking to me, and the ones listening to me." -- Pego the Jerk
All solid planets already have evidence for most of these features. What has previously made the Earth unique is Plate Tectonics, a form of Global Tectonics. It allows the recycling of both the atmosphere and crustal rocks within an extended carbon cycle, which in turn produces much more complicated minerology. The Earth's surface is very young compared to most planets, both through constant erosion, and renewal from sea-floor spreading and high levels of volcanism.
Mars is nearly or completely dead, but it would be very interesting if it once had plate tectonics, because it tests either 1) the prediction that plate tectonics requires massive oceans (to lubricate subduction zones), or 2) the prediction that Mars never had a global ocean.
-- IANAL, BIPOOTV
To me, the best evidence for water is this map, which they always show at NASA presentations on Mars. It's a topographic map colored by altitude, and you see that the areas below a certain depth are almost completely crater-free, contrasted strongly with the areas above that depth. This, to me, is a really, really strong argument that it was once covered in water and had a coastline.
Looking at that map always makes an Earth-like Mars seem much more real to me.
xkcd.com - a webcomic of mathematics, love, and language.
When I interned at NASA/Langley Research center, I heard constantly about the ARES Project, which they're going to use to survey Mars's magnetic field in much greater detail than the global surveyor (among other things).
And it will be the first airplane flight over another planet's surface, just 100 years after the Wright brothers first did it here.
xkcd.com - a webcomic of mathematics, love, and language.
Mars' atmosphere is drastically thinner than ours, and that is assumed to be in a large part due to the smaller size. The gravitational pull simply can't maintain a thick atmosphere, and Mars' size is such that the core has cooled off, and techtonic activity has stopped. Lack of techtonic activity means that atmospheric gasses are no longer being replenished. It may be possible that life could exist without an atmosphere, but it seems very unlikely to me. There would at least need to be a liquid medium to distribute metabolic chemicals (such as CO2 and O2 on earth) to allow for life to have the proper energy to survive. On Mars this would have to be on the surface, as the lack of techtonic activity means there would be no thermal vents such as on earth which provide another chemical gradient which allows some forms of life to survive. I don't have a problem seeing that life could have existed at one time on mars, but I highly doubt that it is currently there. There may be some remnant organisms in deep deep stasis which are basically waiting for favorable conditions to revive, but I personally do not call that currently living.
I'll never make that mistake again, reading the experts' opinions. - Feynman
The other reply is probably correct; this was before water had precipitated out to form oceans and so on. Additionally, whatever got thrown up into orbit was hot: any water ejected would have certainly been vaporous. The material from which the moon is made -- part of the evidence that bolsters the Giant Impact theory -- appears to have literally boiled around the time of the moon's formation, which burnt off most of the lighter chemicals:
Liberty in your lifetime
Of course, the earth could get freeze if it gets knocked out of its orbit and wanders interstellar space effectively forever.