by On April 17, a team of researchers published a study that could be the strongest indication of extraterrestrial life-on a massive planet called K2-18b. The planet is not in the earth’s solar system and circles a star 124 light years away.
The report published in the Astrophysical Journal Letters showed that there could be an ocean world in K2-18B that is able to organize “microbial life”, which is the basis of the earth biosphere and is essential for all life on earth.
The research team, which consists of British and US astronomers, discovered two chemicals in the atmosphere with the James WebB World Camp Telescope. The chemicals fall under the “bisignatures” category and could indicate an extraterrestrial lifespan: dimethyl sulfide (DMS) and dimethyldisulfide (DMDS).
“This is a revolutionary moment,” said Nikku Madhusudhan, astronomer at the University of Cambridge and one of the study authors, at a press conference on Tuesday. “It is the first time that humanity has had potential biosignatures on an habitable planet.”
What is K2-18B?
NASA categorizes K2-18B as a “exoplanet” or as a planet outside the solar system, which circles a star that is not the sun. K2-18B is about 8.6 times larger than the earth and about 700 trillion miles away in the constellation Leo. It circles its star every 33 days, which means that it is closer to its star than the earth in the sun.
In September 2023, the NASA Webb Telescope team reported that K2-18B could be a Hycean Exoplanet, which means that there could be liquid oceans and other molecular properties that would potentially habit the exoplanet.
“Hycean planets open up a completely new avenue in our search for life elsewhere,” said Madhusudhan in another report from 2021.
The two chemicals, which were recently detected near K2-18B DMS and DMDS, are produced on the ground by Marine Phytoplankton and Bacteria.
Researchers have been investigating K2-18b since 2021, but it is not the first exoplanet to be examined. Scientists have found around 5,800 exoplanets since the 1990s.
Research does not say that aliens live on K2-18B
Madhusudhan described the study on Wednesday as “the strongest evidence … there is a possible life”, but the researchers behind this study do not say that there are aliens on K2-18b.
Instead, the results found that K2-18B experienced a biological process that the earth was subjected to billions of years ago.
Researchers need a five-Sigma result to be as safe as possible that their results are true. The latest research only provides a three-Sigma result.
“I can realistically say that we can confirm this signal within one to two years,” Madhusudhan told BBC.
Even if the research team hits this result of five Sigma, it is not a conclusive proof that there is a life in KB-18B. You still have to find out where the DMS and DMDS come from to K2-18B.
“This could be the turning point”
Astronomers have been discussing whether life could exist on K2-18B since 2023, Space.com reported in March. This new research is a step to answer whether life beyond the earth could exist.
“This could be the turning point on which suddenly the basic question of whether we are alone in the universe is one that we can answer,” said Madhusudhan.
