methane as the first clue

Research is ongoing. Tirelessly. But scientists still haven’t found any traces of life anywhere else in the universe. Therefore, high hopes are pinned on the James-Webb Space Telescope. In fact, this will open access to important information about the atmospheres of exoplanets. And researchers are now clarifying under what circumstances the detection of methane (CH4) can be considered a convincing sign of life.

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Methane. With the chemical formula CH4. It’s powerful greenhouse gas. Which we may soon have to hunt. Just like we’re already chasing carbon dioxide (CO2). To limit global warming anthropogenic. But UC Santa Cruz researchers (USA), methane is offered to hunt in a completely different place than the atmosphere of our Earth and for a completely different reason. Because in atmosphere exoplanets, this could mean the presence of extraterrestrial life forms.

in methane as a biosignature – a sign that some form of life has passed. That astronomers especially interested in it today. Because it could be detected in the atmosphere of some exoplanets thanks to the James Webb Space Telescope (JWST). But be careful! Methane can indeed be released as a result of non-biological processes.

In anticipation of the first observations of JWST, the researchers studied this issue. Following their reasoning, it should be remembered that methane does not stay long in the atmosphere. In just a few years it was destroyed photochemical reactions. Thus, the only explanation for the detection of methane in the atmosphere is the presence of a source that releases it more or less continuously.

Biosignature or not, the main thing is not to make a mistake

And it is possible that non-biological sources also emit a lot of methane. From volcanoesreactions occurring, for example, in environments such as mid-ocean ridges, fireplaces hydrothermal vents or areas subduction tectonics or comet impacts orasteroids. But now researchers at the University of California suggest that these sources will then inevitably generate other observable clues in parallel that give away the origin of all this CH.4. in degassing volcanoes, for example, would add methane and carbon to a rocky exoplanet’s atmosphere. carbon monoxide (CO). What biological sources would not do.

Thus, according to astronomers, if methane can provide an important clue, it remains just a simple piece of the puzzle. extraterrestrial life. A study published in Proceedings of the National Academy of Sciences (USA) offers some recommendations to avoid “false positives”. To also prevent researchers from unfortunately missing out on the real biosignature.

For example, on rocky planet in orbit around star Like our Sun, methane can begin to form a reliable biosignature if said planet’s atmosphere also contains CO.2 and if CH4 much more than CO. But when it comes to extraterrestrial atmospheres, there is still a lot to learn. And researchers at the University of California are calling for more work on the subject. Research that could analyze even the most unusual mechanisms of non-biological methane production. To avoid, as far as possible, errors in the interpretation of the results, which may soon be transmitted James Webb Space Telescope.

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