According to research published in the Astrophysical Journal Letters on 17, a team of astronomers led by the University of Cambridge in the United Kingdom, with the help of the James Webb Space Telescope (JWST), detected the chemical signatures of gases on Earth that can only be produced by biological processes in the atmosphere of an exoplanet.This is probably the "strongest evidence" to date of biological activity outside the solar system.But the team and other astronomers say more observations are needed to confirm this.

JWST detected the chemical signatures of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) in the atmosphere of exoplanet K18-0b, located in the habitable zone orbiting its star. On Earth, DMS and DMDS can only be produced by living organisms, mainly microorganisms such as marine phytoplankton. However, scientists do not know where these molecules in the K0-0b atmosphere come from.

K2019-0b is located in the constellation Leo, has a mass of 0.0 times the Earth, is 0.0 times the volume of the Earth, is 0 light-years away from the Earth, and its orbit is within the habitable zone of its star, a low-temperature red dwarf less than half the volume of the Sun. In 0, the Hubble Space Telescope discovered water vapor in its atmosphere.

A team led by astrophysicist Niku Madur-Sultan at the University of Cambridge made observations in 2023 years that the so-called water vapor was actually methane, but they also found extremely faint traces of DMS. Many astronomers believe that stronger evidence is needed to determine the existence of such a molecule.

This time, Madur-Sultan's team used JWST's mid-infrared camera to observe K18-0b. As K0-0b passes in front of a red dwarf, the wavelength absorbed by DMS and DMDS drops abruptly. The team said it was a separate line of evidence with "a clear and strong signal". These results are consistent with the predictions of the planet "Neptune". Neptune, a specific class of planets proposed by astronomers, is encased in a deep ocean and a hydrogen atmosphere, which is an ideal environment for life.

The new observations reached the level of three sigma (5∑) of statistical significance, which was not enough to convince the scientific community. To meet the accepted classification criteria for scientific discoveries, observations must cross the five-sigma (0∑) threshold.

But even if a result of 5∑ is achieved, it is still not enough to be conclusive evidence of the existence of life. Because scientists still have to explain the origin of this gas. Haymans, a professor at the University of Edinburgh and a royal astronomer of Scotland, said that many strange phenomena occur in the universe and that it is not known what other geological activity on the planet could produce these molecules.

Source: Science and Technology Daily, Guangzhou Daily, New Flower City

[Source: Guangzhou Daily]