The strongest hint of biological activity outside the solar system

Using data from space telescope James Webb (JWST), astronomers, led by the University of Cambridge, they discovered the fingerprints of the finger dimethyl sulfide (DMS) and/or Dimetyl disulfid (DMDS), in the atmosphere of the exoplanet K2-18B, which is built into the zon zone.

On Earth, DMS and DMDs are produced only by life, primarily with a microbial life like a sea phytoplacton. Although an unknown chemical process is perhaps the source of these molecules in the atmosphere of K2-18B, the results are the strongest evidence, it adds that life can exist on planets outside our solar system.

The observations have reached the level of “three sigme” statistical significance-which means that there is a likelihood of 0.3% that they occurred accidentally. In order to come up with the accepted classification for scientific discovery, observations would have to cross the prag with five sigmes, which means that it will be below 0.00006% likelihood that occurred by accident.

Researchers say that between 16 and 24 hours of observation time with JWST can help them achieve all important significance with five sigma. Their results are reported in Letters of astrophysical magazines.

Early observations of K2-18B-Koja is 8.6 times massive and 2.6 times larger than the Earth, and in the atmosphere the 124 light year in the constellation of the Leo is identified methane and carbon dioxide. This is the first time that carbon -based molecules have been discovered in the atmosphere of exoplanets in the settlement zone. These results were in line with the predictions for the ‘Hycean’ planet: the world covered with the ocean below the atmosphere rich in hydrogen.

However, the second, weaker signal, hinted at the possibility that something else was happening on the K2-18B. “We didn’t know for sure if the signal we saw last time because of DMS, but only a hint was exciting enough to have another view with JWST using a different instrument,” said Professor Nikka Madhusudhan of the Cambridge Institute of Astronomy, which was conducted by research.

In order to determine the chemical composition of the atmosphere of distant planets, astronomers analyze light from their home star as the planet crosses or passes in front of a star as seen from the ground. As K2-18B transposes, JWST can detect the fall of the starry brightness, and the small part of the star passes through the atmosphere of the planet before it reaches the ground. The absorption of some stars in the atmosphere of the planet is imprinted in a star spectrum that astronomers can compose to determine the component gases of the exoplanet atmosphere.

Previously, the conditional conclusion of DMS was made using JWST Niriss (near infrared paintings and sliding spectrographers) and Nirspec (near infrared spectrograph), which together cover the wavelength range (0.8-5 microns). The new, independent observation was used by JWST’s Miri (middle infrared instrument) in the range of medium infrared (6-12 microns).

“This is an independent line of evidence, using a different instrument than we did before and a different range of light wavelengths, where they do not overlap with previous observations,” Madhusudhan said. “The signal passed strongly and clearly.”

“It was an incredible realization when the results emerged and remained consistent during the extensive independent analyzes and slave tests,” said co-author Måns Holmberg, researcher of the Institute for Scientific and Scientific-Itelloscope in Baltimore, USA.

DMS and DMD are molecules of the same chemical family, and both are predicted to be biosignations. Both molecules have overlapping spectral features in the perceived wavelength range, although further observations will help to distinguish between two molecules.

However, the concentrations of DMS and DMD in the K2-18B atmosphere are very different than on the ground, where they are mostly below one billion by volume. The K2-18B estimates that thousands of times are stronger-over ten parts per million.

“Early theoretical work envisaged that high levels of sulfur-based sulfur gases such as DM and DMD are possible at Hycean worlds,” Madhusudhan said. “And now we have noticed it, in accordance with what is scheduled. Given everything we know about this planet, the Hycean world with the ocean that is full of life is a scenario that best suits the data we have.”

Madhusudhan says that although the results are exciting, it is vital to get more data before claiming that life was found in another world. He says that although he is cautiously optimistic, there may be unknown chemical processes earlier at the K2-18B that can explain observations. Working with colleagues, he hopes to carry out further theoretical and experimental work to determine whether DMS and DMDs can produce non-biologically at the current level currently concluded.

“The conclusion of these biosignation molecules asks deep questions that concern the processes that could produce them,” said co -author Subhajit Sarkar of Cardiff University.

“Our work is the starting point for all investigations that are now needed to confirm and understand the implications of these exciting findings,” said co -author Savvas Constantinou, also from the Cambridge Institute of Astronomy.

“It is important that we are deeply skeptical of our own results, because only by testing and recurring that we will be able to reach the point where we are sure of them,” said Madhusudhan. “So science has to work.”

Although not yet claimed by the final discovery, Madhusudhan says that with powerful tools like JWST, the future of the planned telescope, humanity takes new steps according to the answer to the most important for questions: Are we alone?

“Decades from now, we can look back at this time and recognize that when it is when the living universe came near,” Madhusudhan said. “This could be a turning point, where it is suddenly a fundamental question of whether we are alone in the universe the one we are able to answer.”

The James WebB space telescope is NASA -e, ESA -ei Canadian Space Agency (CSA). The study is supported by British research research (Urkri) Frontier Research Grant.