KOMPAS.com – The hunt for new worlds beyond Earth continues. This time, a new study revealed that methane the atmosphere can be a sign of life that astronomers can detect.
Although non-biological processes can produce methane, a study by scientists at the University of California Santa Cruz revealed that a condition could refer to biological activity as a source of methane in the atmosphere. rocky planet.
“Oxygen is often talked about as one of the best biosignatures, but may be difficult to detect with JWST,” said Maggie Thompson, a graduate student in astronomy and astrophysics at UC Santa Cruz and lead author of the new study.
To date, no research has focused on methane as a biosignature or a biological sign of rocky planet life.
“We want to provide a framework for interpreting observations, so if we see a rocky planet with methane, then we know what other observations are needed to make it a persuasive biosignature,” explains Thompson.
New study on the potential of methane as a a sign of planetary life beyond Earthwas published on March 28 in Proceedings of the National Academy of Sciences.
In the study, scientists examined various non-biological sources of methane and assessed their potential to maintain a methane-rich atmosphere.
The idea of methane as a biosignature stems from its instability in the atmosphere.
Because, the photochemical reaction destroys atmospheric methane, it must be continually replenished to maintain high levels of concentration.
“If you detect a lot of methane on a rocky planet, you usually need a large source to explain it,” said co-author Joshua Krissansen-Totton, a Sagan Fellow at the University of California Santa Cruz.
“We know biological activity created large amounts of methane on Earth, and it probably did on the early Earth because making methane is a fairly easy thing to do metabolically,” Krissansen-Totton said.
However, related detection of methane as a sign of life planets beyond Earth, non-biological sources would not be able to produce that much methane without producing observable clues to its origins.
Also read: Scientists Confirm Methane Existence on Mars
In the study of methane in volcanoes, for example, the emission of gases adds methane and carbon monoxide to the atmosphere. While biological activities tend to easily consume carbon monoxide.
The researchers also found that nonbiological processes cannot easily produce a habitable planetary atmosphere rich in methane and carbon dioxide, with little or no carbon monoxide.
This study emphasizes the need to fully consider the planetary context in evaluating potential biosignatures.
The researchers concluded that for rocky planets orbiting stars like the sun, atmospheric methane is more likely to be considered a strong sign of life if the atmosphere also contains carbon dioxide.
They emphasize that methane is more abundant than carbon monoxide, and that the composition of a planet that is very rich in water can be ruled out to detect signs of planetary life beyond Earth.
“One molecule won’t give you an answer, you have to take into account the full context of the planet. Methane is one piece of the puzzle, but to determine whether there is life on a planet, you have to consider its geochemistry, how it interacts with its star, and the many processes that can affect a planet’s atmosphere on geological timescales,” Thompson said.
The study also considers the various possibilities for “false positives” and provides guidelines for assessing the methane biosignature.
The researchers say that further studies are needed to fully understand the detection of methane as a sign of extraterrestrial life.
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