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Old 08 June 2018, 05:22 PM
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Richard W Richard W is online now
Join Date: 19 February 2000
Location: High Wycombe, UK
Posts: 26,399

It's kind of hard to say from just that line. "Organic molecules" mean molecules based on carbon and hydrogen, with the carbon forming chains. If they say they're "strikingly similar" to those on earth then it may imply they've found something more specific, or it may not.

The only molecule that story mentions specifically is methane, which is the simplest organic molecule there is, and by definition it's the same as methane on earth - barring subtle differences in the isotopic ratios and things which are more physics than chemistry, and probably not relevant. They say its presence suggests biological sources when found on earth, but it certainly can arise just from chemical processes too.

The other thing they mention is "gas", which I assume means "gasoline" here. I think it will be the journalist who's used that comparison, though. Crude oil is distilled into various longer-chain hydrocarbons such as ethane, propane, butane and so on (distinguished by the number of carbons in the chain - methane = 1, ethane = 2, propane = 3 etc...). Again, these are pretty simple molecules that can arise from various processes, but on earth, crude oil is the fossilised and compressed remains of biological life. By definition if these are the molecules they've found they will be "strikingly similar" to the same molecules on earth, but again, the comparison with fossil fuels is misleading because they can come from other processes, and they're very simple molecules.

If they've found anything more complex than that, it's not evident from the article. On the other hand, just finding carbon chains is interesting in itself - they are the "building blocks of life" as it says, but finding the blocks doesn't imply they've actually been built into life in the past and then fallen apart again.
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