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Lake spotted on Titan?
jahead writes "It looks like
a lake has been seen on Saturn's moon Titan by the Cassini probe. But don't get too excited yet. As mentioned by Elizabeth Turtle in the article, it could also be a dried up lake that left dark deposits."
Liquids require pressure (see this) while solids and gasses don't, and pressure is a rare thing in space.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Actually Methane gas has no odor. We add impurities to it in order to make it detectable.
I think the evidence points to lots of ancient volcanism, but no current activity. Venus does have lots of atmosphere and pressure, but it's probably been dry on the surface for a long time now.
Wrong planet, wrong moon. Europa is a moon of Jupiter. Titan is a moon of Saturn.
What we mean to say is that on planets that have any kind of atmosphere, there will be some kind of fluid present. If you look at a phase diagram (crack out your old chem books), you'll realize that liquids can only exist at certain temperatures and pressures before becoming either solid or gas. As the majority of space is rather cold and the pressure is rather low, this tends to favor the formation of solids and gases.
As for your venus question, I would venture to imagine that lava, as a higly viscous fluid would remain liquid at a relatively low pressure. The other mention is that the surface of venus is basically a massive cooking oven from all of the cloud cover of various Sulfur oxides, which would provide both sufficient temperature (from the greenhouse effect) as well as indicate a high amount of atmospheric pressure.
What's significant about this was that it was initially hypothesized that since titan had a considerable atmosphere of methane and other hydrocarbons, that the surface of Titan was possibly covered in either a massive liquid methane ocean or a methane ice sheet. However once the Huygens probe landed, that hypothesis was disproved (the one about liquid methane on the surface).
With what looks like a lakebed (even if it's dry) on the surface of Titan, this provides evidence that there once was/still is some liquid which eroded the landscape, which confirms that Titan's atmosphere may be more substantial than other planet's and that it may be more like earth.
Come on... even us ignorant off-worlders are smart enough to know that methane won't burn in the absence of oxygen.
-CausticPuppy "Of all the people I know, you're certainly one of them." -Somebody I don't know
Sunlight breaks down methane, so to have it in Titan's atmosphere (particularly at such high levels) it has to be continually replaced. You can make methane on Titan via either life or some sort of weird chemical process. So the methane is a hint at possible life.
:)
o duct-presentations.cfm has lots of good inside information about the science results... the end of the "Titan: First Views of an Alien World" discusses where to look for life on Titan)
Titan's atmosphere is also full of a haze of complex organic molecules that continually rain down on the surface... leaving deposits of hydrocarbons on the surface hundreds of meters thick.
Now if only these complex organics could get mixed in with water. (And it has to be water, because you need the oxygen). Guess what 'rocks' on Titan are made out of
So you might have something happening in this methane lake with methane being the liquid and oxygen coming from ice... but this would be completely different from life as we know it...
My own bet is on the volcano to look for life (The volcano on Titan erupts molten water). Also there might be life in Titan's mantle (it's made of liquid water + ammonia mixture).
(This website: http://saturn.jpl.nasa.gov/multimedia/products/pr
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