Craters Quickly Hidden On Titan 39
MightyMartian writes "NASA scientists say Cassini has discovered that far fewer craters are visible on Titan than on the other moons of Saturn. The craters they have discovered are far shallower than other moons' craters and appear to be filling with hydrocarbon sand. On top of being another reason Titan's active geology is very cool, it adds to the mystery of where all the methane on Titan is coming from. 'The rain that falls from Titan's skies is not water, but contains liquid methane and ethane, compounds that are gases at Earth's temperatures. ... The source of Titan's methane remains a mystery because methane in the atmosphere is broken down over relatively short time scales by sunlight. Fragments of methane molecules then recombine into more complex hydrocarbons in the upper atmosphere, forming a thick, orange smog that hides the surface from view. Some of the larger particles eventually rain out onto the surface, where they appear to get bound together to form the sand.'"
Re:Titan's active geology is very cool (Score:5, Insightful)
The source of Titan's methane remains a mystery because methane in the atmosphere is broken down over relatively short time scales by sunlight
Hang on a minute: wasn't free methane being used as an indicator of life on Mars? So where does this methane come from?
Kind of. Methane could be generated on Mars either by biological means, or by geological means.
If its geological, then the sub-surface of Mars is more active than we thought.
If its biological in origin, well there's the biggest discovery in human history right there.
For the record, im guessing geological.
Ultra-dense atmosphere at fault? (Score:5, Insightful)
Wouldn't Titan's ultra-dense atmosphere have something to do with this? Most meteors come in at a high angle of incidence, meaning they graze the atmosphere, then fall in as they're slowed down to a capture speed.
Titan's atmosphere is something like what, three times as dense as Earth's atmosphere? It's up there with Venus, not Mars or Io, so shouldn't we be comparing it to planets, not moons? Keep in mind that visually, Titan is only about 8% smaller than Mars, and quite a bit larger than Earth's moon.
Re:Wild theory (Score:5, Insightful)
Yeah its interesting but it should be possible to calculate the amount of biomass required to do that. There is a hell of a lot of methane in this cycle on Titan which implies a lot of life. My guess is that the stuff would have to blanket the planet and it would need a fast metabolism. For me that means it must be in a subsurface ocean. The surface is too cold for a high energy metabolism.