Scientists have found the best ever hint of alien life on another planet. But they aren’t getting entirely excited just yet.
In what might eventually be hailed as the first fingerprint of extraterrestrial life outside of our solar system, scientists found gases that as far as we know are only produced by biological processes.
As such, the findings appear to be a “biosignature”, or a sign of possible life. But there is much left to do before researchers can be sure.
What did the scientists find?
The new work looked at the planet K2-18 b, which is 8.6 times as massive as Earth, 2.6 times as large and sits about 124 light years away. It was already an exciting place to look, since it orbits in the “habitable zone” around its star where water can exist and not immediately freeze or turn to gas.
It became more exciting in recent years. Previous observations from the James Webb Space Telescope had found methane and carbon dioxide in the planet’s atmosphere, and that was the first time that carbon-based molecules were found on a planet that is in its star’s habitable zone.
But now researchers have found two gases: dimethyl sulfide, or DMS, and dimethyl disulfide, or DMDS. On Earth, that would mean that those gases are coming from life.
Why does that mean aliens?
That seems to be the best explanation we have of the strange data. As far as we know, and at least on Earth, DMS and DMDS are made on Earth only by living organisms, primarily algae.
“The only scenario that currently explains all the data obtained so far from JWST (James Webb Space Telescope), including the past and present observations, is one where K2-18 b is a hycean world teeming with life,” said astrophysicist Nikku Madhusudhan of the University of Cambridge’s Institute of Astronomy, lead author of the study published in the Astrophysical Journal Letters.
“However, we need to be open and continue exploring other scenarios.”
But are they real?
Nobody knows for sure, and scientists both involved in and away from the research have advised everyone to be cautious. The data is is only an indicator of a possible biological process, not anything like the discovery of actual organisms.
Further work will be required before anyone is authoritatively able to say anything for sure – and thankfully that work will be starting very soon.
“The rich data from K2-18 b make it a tantalising world,” said Christopher Glein, principal scientist at the Space Science Division of the Southwest Research Institute in Texas. “These latest data are a valuable contribution to our understanding.
“Yet, we must be very careful to test the data as thoroughly as possible. I look forward to seeing additional, independent work on the data analysis starting as soon as next week.”
