Astronomers find the most significant evidence of the existence of extraterrestrial life
17 April 18:28
Scientists have found traces of two chemical compounds in the atmosphere of the distant planet K2-18b, the origin of which is associated with the vital activity of organisms. So far, this is the most convincing evidence that alien life does exist.
This was reported by The New York Times, "Komersant Ukrainian" reports.
The massive K2-18b is located outside the Solar System – it orbits a star at a distance of 120 light years from Earth. The exoplanet was discovered in 2015 by Canadian scientists using data from the Kepler space telescope. K2-18b is a so-called sub-Neptune: a planet larger than an Earth-type object but smaller than gas giants like Neptune.
In 2021, the team of Cambridge University astronomer Nikku Madhusudhan suggested that some sub-Neptunes might have oceans of warm water under an atmosphere rich in hydrogen, methane, and other carbon compounds. The researchers coined a new term for such bodies – Hycean.
After the launch of the James Webb Telescope in December 2021, it was possible to learn more. When K2-18b passes near its star, its atmosphere brightens and the gases change the color of the light. This made it possible to analyze the chemical composition of the planet’s atmosphere.
In 2023, scientists found faint signs of dimethyl sulfide (DMS), a molecule that is produced on Earth by living organisms, including seaweed. It is this substance that gives the sea its characteristic odor.
Last year, the atmosphere of K2-18b was analyzed again using another instrument of the Webb telescope. The signal of dimethyl sulfide was even stronger than that of a similar molecule, dimethyl disulfide.
It turned out that K2-18b may contain thousands of times more DMS than is found on Earth. This suggests that its oceans are teeming with life. However, experts warn that it is necessary to investigate this topic more thoroughly. They want to find out whether K2-18b is really a Hycean-type planet or just a hot rock giant with magma and a hellish hydrogen atmosphere.
