Astronomers have detected dimethyl sulphide on K2-18b, the strongest evidence yet for life on another planet.
Astronomers have made the strongest evidence yet for life on another planet, according to researchers who used the James Webb Space Telescope (JWST) to observe the exoplanet K2-18b. The detection of ‘dimethyl sulphide (DMS)’ and a possible related molecule called ‘dimethyl disulphide (DMDS)’ in the atmosphere of K2-18b has sparked excitement among scientists, but also caution.
K2-18b is a super-Earth exoplanet located in the constellation of Leo.
It orbits a small, cool star and has a surface temperature that could support liquid water.
NASA's Spitzer Space Telescope detected water vapor in K2-18b's atmosphere using spectroscopy.
The planet's size and atmospheric composition make it a potential candidate for hosting life.
Further research is needed to confirm these findings and learn more about this intriguing exoplanet.
K2-18b is a promising place to look for life. Located 124 light years away from Earth, it orbits a star that sits in the habitable zone, where liquid water can exist. In 2015, astronomers first discovered the exoplanet and soon established that it was a promising place to search for life.
In 2023, researchers used JWST to observe K2-18b’s atmosphere and found evidence of water vapour, carbon dioxide, and methane. However, they also detected a weak signal for ‘DMS’ , which is produced only by living organisms on Earth. Now, Madhusudhan and his colleagues have used a different instrument from JWST to observe K2-18b again, finding a much stronger signal for ‘DMS’.
Madhusudhan is a Sanskrit name that translates to 'possessor of great fortune' or 'good luck'.
In Hindu mythology, there are several characters named Madhusudhan.
One notable figure is Madhusudhan, the son of King Indra and the goddess Sachi.
He is often depicted as a brave warrior and is associated with good fortune and prosperity.
The name Madhusudhan has been popular in India for centuries and is still used today.
The team claims that the detection of ‘DMS’ and ‘DMDS’ is at the three-sigma level of statistical significance, which means there’s only a 3-in-1000 chance that the data is a fluke. This is equivalent to a 5-sigma threshold in physics, which equates to a 1-in-3.5 million chance that the data is a chance occurrence.
However, other scientists are more sceptical about the findings. They argue that alternative explanations for the signals could exist and that the evidence needs to be verified by other groups before it can be confirmed.
The team estimates that between 16 and 24 hours of further observations with JWST could help them reach the five-sigma level, but they can’t guarantee this due to the difficulty of observing the planet’s atmosphere. If further observations prove the discovery, it would be a ‘tremendous advance’ in the search for life beyond Earth.
Madhusudhan says that even if the signal proves to be non-biological, the finding is still important. ‘This is a revolutionary moment, fundamentally to me as an astronomer, but also to our species – that we have been able to come from single cellular life, billions of years ago, to an advanced technological civilization which is able to peer through the atmosphere of another planet and actually find evidence for possible biological activity,’ he said.
The discovery of ‘DMS’ and ‘DMDS’ on K2-18b has sparked excitement among scientists, but also caution. Ruling out alternative mechanisms could take some time, and the question may never be fully resolved with the limited data exoplanets offer. However, if further observations can prove this is a real discovery, it would be a ‘tremendous advance’ in the search for life beyond Earth.
- newscientist.com | Astronomers claim strongest evidence of alien life yet
