New Studies Doubt Mars Water Theory

An anonymous reader writes "Two groups of scientists have doubted the Mars rover scientists' theory that Mars was drenched with water for a significant time. If their dry Mars theories are supported, it is unlikely that life ever existed on Mars. The first group say that rock features that indicate water are actually caused by meteorite impacts. The second group argue that these features are caused by volcanic activity. Steve Squyres, the Mars rover lead scientist, is sticking by his original findings."

Comments

Life on Mars

[jgardn]

Sorry to rain on everyone's parades here, but to find any signs of life on Mars would really damage the current theory of how life got to be here.

See, the chances of life spontaneously being created on a planet is so astronomically small as to be almost impossible. The universe is vast, and finding a handful of other planets in different galaxies that also bore life at one point in their histories would corroborate this. In fact, finding no planets with any signs of life corroborates it even better.

However, if we find life on our next door neighbor, we have some explaining to do. How did life get there? Was it transplanted from earth? Or was earth life transplanted from Mars? If life can propogate across the void of space between earth and Mars, what's to stop it from propogating across solar systems and perhaps even galaxies in astronomical time scales? How old is life anyway, and where did it really come from?

All of a sudden, earth won't seem so unique anymore. And we'll start wondering why SETI hasn't turned anything up yet.

Now, if we found HUMAN life on Mars, that would really destroy all of the ongoing theories of the origins of life on earth. Either we are a spacefaring species and thus earth is not our home, or somehow, despite all odds, humanity has evolved on two separate planets that just happen to be right next to each other.

I can't predict reliably one way or the other, but my guesses are that Mars is a dead as the moon. As with anything in science, it's the surprises that are interesting here.

Re:Life on Mars

[meringuoid]

However, if we find life on our next door neighbor, we have some explaining to do. How did life get there? Was it transplanted from earth? Or was earth life transplanted from Mars? If life can propogate across the void of space between earth and Mars, what's to stop it from propogating across solar systems and perhaps even galaxies in astronomical time scales? How old is life anyway, and where did it really come from?

Well, the chances of Mars life reaching Earth, or of Earth life reaching Mars, are pretty good. The two planets are close together; chances are that sooner or later a rock is going to get knocked from one to the other with some spores on board. I would not be at all surprised to find that Mars life (if it exists) and Earth life share a common ancestry.

However, the interstellar spread of life seems less likely to me. While it's quite likely that a rock from Earth might by chance find its way to Mars, it's very unlikely that it would ever escape the solar system entirely. The energy needed to leave the Sun behind is enormous, and the odds of a loose rock ever actually getting somewhere of interest are minute. If life spreads from star to star, it'll do so because it's evolved a form capable of building starships.

Now, if we found HUMAN life on Mars, that would really destroy all of the ongoing theories of the origins of life on earth. Either we are a spacefaring species and thus earth is not our home, or somehow, despite all odds, humanity has evolved on two separate planets that just happen to be right next to each other.

I don't think anyone sane is suggesting that that's likely to happen.

Re:Life on Mars

[Tango42]

If life can propogate across the void of space between earth and Mars, what's to stop it from propogating across solar systems and perhaps even galaxies in astronomical time scales?

The nearest galaxy to ours is 25,000 ly away. Even assuming a speed of 1% of the speed of light, which is very fast, it would take 2.5 million years to get there. Considering 0.01c is over 1000 times faster than the escape velocity of the galaxy at the position of the sun, it's not a very realistic speed, so the actual time will be much larger. If random bits of life go off in random directions they're unlikely to meet anything any time soon, so it will probably take billions of years before something goes in the right direction and then billions of years for it to get there - astronomical time scales would be at most 10 billions years or so(the universe is less than 15 billion years old by the last estimate I read, and it takes some time for galaxies, stars, planets and finally life to form), so the chances are very very slim, although prehaps not impossible.

Life transporting between stars is easy enough though. A meteor hits earth, a bit of rock flies off and ends up in either earth or solar orbit (probably wouldn't fly off fast enough to leave the solar system), the bit of rock then gets hit by a comet on a parabolic course from the oort cloud going in towards the sun and then out towards another star, the rock sticks to the comet, is carried to the other star where it crashes into a planet. Over the 4 billions years or so that life has existed on earth, that could easilly have happened.

You are nuts

[MarkusQ]

See, the chances of life spontaneously being created on a planet is so astronomically small as to be almost impossible.

That's nuts. The chances of life arising spontaneously (note: not "being created") are quite high. The individual steps are reproducible in the lab, and the overall process is quite simple. Given a heterogeneous goop capable of forming complex molecules (e.g. water with a normal assortment of space stuff), a flow of energy (source and sink) and enough time, life is pretty much inevitable.

-- MarkusQ

Mars debate oddly constrained

[strangedays]

A couple of observation related to this running mars debate that bother me.

1. I have never seen NASA publications publicly reference the excellent work and results produced by ESA. I follow this discussion with considerable curiosity and have noticed this for a while now. NASA sources and publications seem to debate the topics as if other scientific sources of information were unavailable? This article subtly discusses the debate as if the theories had to be based solely on Mars Rover data, which is bogus. Take a look at the excellent info published openly here: http://www.esa.int/SPECIALS/Mars_Express/index.htm l
2. The whole debate about standing surface water seems slightly off focus. ESA has lots of evidence now for subsurface water and even standing surface water ice. Lots of life on earth exists in the soil and subsurface, where life can survive hostile surface changes, which is true even on Earth. So thats where we should look... duh. Free standing but transient lakes of meltwater, seem like poor venues for life, given the mars atmosphere and general geological data. IANA Geologist or xenobiologist, but who needs to be, to see that one coming? The NASA spin doctors know that the Mars rovers run around on the surface, so thats where they think the scientific debate must be?

<Swift Wild Ass Speculation>

Nasa Mars articles are subtly and covertly constrained by NASA media censors because of the political and funding sensitivites ?

</SWAS>

If so, thats really bad, and should be stopped.

If they are not constrained, then the scientists themselves give the perception of ignoring ESA data or references, which I find impossible to believe.

Are my observations at fault? Is there a pragmatic and reasonable explanation why this debate seems so oddly limited in scope and reference to ESA etc?