Scientists have detected what they say is the strongest evidence yet that life may exist beyond Earth. A University of Cambridge team studying the planet K2-18b found signs of molecules associated with simple organisms.
Announcing the University of Cambridge’s website today, Lead researcher Professor Nikku Madhusudhan said: “This is the strongest evidence yet there is possibly life out there. I can realistically say that we can confirm this signal within one to two years.” The James Webb Space Telescope detected chemical traces such as dimethyl sulphide, a gas produced by marine plankton on Earth.
Researchers estimate the level of this gas could be thousands of times higher than found in Earth’s atmosphere.
K2-18b lies 124 light years and 700 trillion miles away and is about 2.5 times Earth’s size, orbiting a red dwarf star.
Some scientists believe the planet contains a vast ocean, though others suggest molten rock or a gas giant structure.
More data is needed to confirm the signal and rule out non-biological explanations.
While cautious not to overstate the case, Prof Madhusudhan stressed the strength of the data – gathered using a different instrument and a distinct wavelength range from the team’s earlier observations.
Speaking to Nick Robinson on BBC Radio 4’s Today programme, he said: “It’s a transformational moment in astronomy and and in science, because this is one of the longest standing questions in the history of science, are we alone? And what we may be seeing the first signs of being able to answer that question.
“This is certainly in exoplanetary science and in my career, about the as as great as it gets. But I think even in the broader history of astronomy, this is one of the pinnacle moments. If this turns out to be true, this will be one of the defining moments of modern astronomy.”
The presence of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) – gases that on Earth are produced exclusively by life – points to a scenario consistent with a living, ocean-covered Hycean world, he explained.
He stressed: “The observations that we’re making, the detections we’re making, that at what is known as a three sigma level.
“So there is still a 0.3% chance that it might be a statistical fluke.
“So we want to be really, really thorough and make more observations and get the evidence to the level that there is less than one in a million chance of it being a fluke.”
The research was published in The Astrophysical Journal Letters.
