by Scientists believe that they have discovered the strongest signs of extraterrestrial life on a distant ocean planet that goes far beyond our solar system.
The possible landmark discovery was made by scientists from the James Webb World Card telescope, the chemical fingerprints of gases that are only used in biological processes on earth in the atmosphere of the alien planet.
The two gases – dimethyl sulfide or DMS as well as dimethyldisulfide or DMDS – are generated primarily by microbial lifespan in webbs.
Researchers believe that the gases are a sign that the planet “teemances” with microbial life.
However, they emphasized that they are not the discovery of the actual living organisms, but a possible bisignature – an indicator of a biological process – and that the results should be viewed carefully, further observations are required.
Nevertheless, they remained excited.
These are the first indications of an alien world that may be inhabited, said astrophysicist Nikku Madhusudhan from the Institute for Astronomy at the University of Cambridge, leading author of the study published in the Astrophysical Journal Letters.
Madhusudhan asked about the possibility of an intelligent or other life of foreign life and said: “We will not answer this question in this phase. The basic assumption is a simple microbial life.”
“This is a transforming moment when looking for life beyond the solar system in which we showed that it is possible to recognize biosignatures in potentially habitable planets with current facilities. We have entered the era of observation astrobiology,” added Madhusudhan.
The scientist found that various efforts are made in our solar system to search for signs of life, including various environments that could be beneficial for life in places such as Mars, Venus and various icy moons.
K2-18 B is 8.6 times the size of our planet.
It circles in the “habitable zone” – a distance in which liquid water, an important part of life, can be present on a planetary surface – around a red dwarf star that is smaller and less bright than our sun and is about 124 light years from the earth in the constellation Leo.
A light year is the distance light in one year, 9.5 trillion km (5.9 trillion miles). Another planet was also identified to circle this star.
Around 5,800 planets beyond our solar system called Exoplanets have been discovered since the nineties.
Scientists have named the existence of exoplanets called Hycean worlds – covered by a liquid water habitable by microorganisms and with a hydrogen -rich atmosphere.
Previous observations by WebB, which was launched in 2021 and became in operation in 2022, had identified methane and carbon dioxide in the atmosphere of K2-18 B, which for the first time that molecules on a carbon basis in the atmosphere of an exoplanet were discovered in the usual zone of a star.
“The only scenario that has currently been explained by JWST (James Webb Space Telescope), including the past and current observations, is one in which K2-18 B is a hyceanic world that would be before life,” said Madhusudhan. “However, we have to be open and continue to explore other scenarios.”
Madhusudhan said that with Hycean worlds, when they exist, “talk about microbial life, possibly like what we see in the earth’s oceans”. Your oceans are considered warmer than the earth.
DMS and DMDS, both from the same chemical family, were predicted as important exoplanet biosignatures.
WebB found that one or the other or possibly both in the atmosphere of the planet with a confidence level of 99.7%, which means that there is still a probability of 0.3% that observation is a statistical coincidence.
The gases were detected in atmospheric concentrations of more than 10 parts per million per million according to volume.
“As a reference, this is thousands of times higher than its concentrations in the earth’s atmosphere and cannot be explained without biological activity on the basis of existing knowledge,” said Madhusudhan.
Scientists who are not involved in the study advise prospect.
“The rich data from K2-18 B make it a tempting world,” said Christopher Glein, director of the Space Science Division of the Southwest Research Institute in Texas.
“This latest data is a valuable contribution to our understanding. However, we have to be very careful in order to test the data as thoroughly as possible. I look forward to seeing additional, independent work on the data analysis that starts until next week.”
K2-18 B is part of the “Sub-Neptune” planetary class with a diameter that is larger than the earth, but less than that of Neptune, the smallest gas planet in our solar system.
The “holy grail” of exoplanet science, said Madhusudhan, was to find evidence of a life on an earth -like planet beyond our solar system. Madhusudhan said that our species have been “alone” in the universe for thousands of years and could now only be in a Hycean world a few years after the detection of a possible alien life.
But Madhusudhan still urged caution.
“First of all, we have to repeat the observations two to three times to ensure that the signal we see is robust and to increase the meaning of recognition to the level at which the likelihood of statistical coincidence is less than one of one million, said Madhusudhan.
“Second, we need more theoretical and experimental studies to ensure whether there is another abiotic mechanism (one that does not affect biological processes) to produce DMS or DMDs in a planetary atmosphere like that of K2-18 B.
“Although earlier studies have proposed robust bisignations even for K2-18 B, we have to remain open and pursue other options,” said Madhusudhan.
The results therefore “a big one” whether the observations are due to life, and it is in “no interest in saying prematurely that we have discovered life,” said Madhusudhan.
