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Can someone elaborate on the relevance of this? I remember reading that scientists hope to find methane on Mars as an indication for life at some point in the p

Can someone elaborate on the relevance of this? I remember reading that scientists hope to find methane on Mars as an indication for life at some point in the past. How does all this petroleum/methane (now propylene) in Titan's atmosphere fit into that?

pyre 13y ago
More complex hydrocarbons are associated with carbon-based life forms (e.g. most of the stuff we use to make plastics come from crude oil which came from the decomposition of carbon-base lifeforms). IIRC, methane is one of the simplest hydrocarbons and thought to be naturally-occurring throughout the universe. Other complex hydrocarbons on the other hand...? (disclaimer: I might be wrong)
ars 13y ago
Methane is not an indication of life. It's too common. But if you can find methane in rock then you can check the rock and see if it's a type that could make methane. For more fun read: https://en.wikipedia.org/wiki/Abiogenic_oil https://en.wikipedia.org/wiki/Abiogenic_oil
Udo 13y ago
As far as indications of life go, we're looking for substances that might have been freshly produced by a biological organism. That's not as easy as it sounds, since we're always discovering new abiogenic processes that make even complex hydrocarbons. Methane is abundant in the universe at large. You can find it in huge quantities in gas giants. There is evidence for seasonal methane deposits on Mars, but so far none of the observations suggest that it has been put there by a life form. Chemistry in space is interesting, because it sheds some light on the early conditions on Earth and other habitable worlds. It was first thought that planets start with only simple elements and more complex molecules would have to be generated by the environment. Now we see increasingly that more complex chemistry is indeed going on in space as well and this in turn means planets do get seeded with more higher-order stuff than previously thought. Spectroscopy suggests that compounds as complex as linked amino acids can and do form in deep space! This is also interesting for biologists since a non-biological origin for these molecules drastically improves the likelihood and timeframe for the formation of carbon-based lifeforms. It also means we're likely to find more amino acid-based life out there, which is nice. Propene in itself is not that surprising of a find, it's more like another piece of the puzzle falling into place. Of course, this all has nothing to do with plastic. That's just bad copy writing in a weak attempt to draw public interest.

pyre 13y ago

More complex hydrocarbons are associated with carbon-based life forms (e.g. most of the stuff we use to make plastics come from crude oil which came from the decomposition of carbon-base lifeforms). IIRC, methane is one of the simplest hydrocarbons and thought to be naturally-occurring throughout the universe. Other complex hydrocarbons on the other hand...? (disclaimer: I might be wrong)

ars 13y ago

Methane is not an indication of life. It's too common. But if you can find methane in rock then you can check the rock and see if it's a type that could make methane. For more fun read: https://en.wikipedia.org/wiki/Abiogenic_oil https://en.wikipedia.org/wiki/Abiogenic_oil

Udo 13y ago

As far as indications of life go, we're looking for substances that might have been freshly produced by a biological organism. That's not as easy as it sounds, since we're always discovering new abiogenic processes that make even complex hydrocarbons. Methane is abundant in the universe at large. You can find it in huge quantities in gas giants. There is evidence for seasonal methane deposits on Mars, but so far none of the observations suggest that it has been put there by a life form. Chemistry in space is interesting, because it sheds some light on the early conditions on Earth and other habitable worlds. It was first thought that planets start with only simple elements and more complex molecules would have to be generated by the environment. Now we see increasingly that more complex chemistry is indeed going on in space as well and this in turn means planets do get seeded with more higher-order stuff than previously thought. Spectroscopy suggests that compounds as complex as linked amino acids can and do form in deep space! This is also interesting for biologists since a non-biological origin for these molecules drastically improves the likelihood and timeframe for the formation of carbon-based lifeforms. It also means we're likely to find more amino acid-based life out there, which is nice. Propene in itself is not that surprising of a find, it's more like another piece of the puzzle falling into place. Of course, this all has nothing to do with plastic. That's just bad copy writing in a weak attempt to draw public interest.