Search for extraterrestrial life: traces of water worlds could already be found
In the search for extraterrestrial life, water worlds have become the focus of research. Now there is a recommendation on what to look out for.
(Image: stockelements/Shutterstock.com)
A research group from the USA has identified a group of organic compounds known as monohalomethanes, which could be discovered as traces of extraterrestrial life on certain exoplanets using existing technology. They could be found by the James Webb Space Telescope. According to the group, this would be possible on large water planets around red dwarf stars if there are organisms in their deep oceans that produce them. The search for this is currently an optimal strategy to search for extraterrestrial life. Smaller rocky planets, which are more similar to Earth and have a much thinner atmosphere, are still too difficult to analyze.
Promising biosignature
Detecting oxygen on Earth-like exoplanets is currently difficult or even impossible, explains study leader Michaela Leung from the University of California, Riverside. Monohalomethanes in the atmosphere of water worlds – or “hypocene planets” (from the English terms for hydrogen and ocean) – on the other hand, are a unique opportunity. These are organic compounds consisting of one carbon atom and three hydrogen atoms, combined with a halogen atom. On Earth, they are primarily produced by bacteria, algae, fungi, and some plants. On exoplanets, they could be detected comparatively easily as a biosignature.
Videos by heise
One of the great advantages of a possible search for monohalomethanes on exoplanets is that, under ideal conditions, they could be found in just 13 hours of observation with the James Webb Space Telescope, says Leung. However, if they were actually detected, it would not yet be known what the organisms possibly responsible for this would look like. The compounds are also so promising because they absorb a particularly large amount of light in the infrared spectrum and are likely to accumulate particularly strongly in the atmosphere of water worlds.
The James Webb Space Telescope is currently the best tool for searching for the compounds, but future missions could find them even faster. The team is relying primarily on an instrument proposed by Europe called LIFE. If the Large Interferometer For Exoplanets is actually built and sent into space, it could confirm the presence of monohalomethanes within a day. If this were successful on several worlds, it could indicate that microbial life is widespread in the universe. But there is still a long way to go. The research work is now being presented in the Astrophysical Journal Letters.
(mho)
