Scientists speak out about reports Nasa telescope found signs of alien life

Better understanding should come later this year, researchers say

Recent excitement about the discovery of signs of alien life on a distant planet could be misplaced – or at least early, according to a new study.

In recent weeks, excitement has grown about a planet called K2-18b, a world around 125 light-years from Earth. Late last year, researchers revealed they may have seen a “life” molecule on that planet.

Since then, speculation and excitement has grown over what could be a sign of life on another world. But the researchers warned that the detection was “not robust” and that further work would be needed to confirm what was happening on the planet.

Now, however, researchers have warned that the signal is not as clear as it might have initially seemed. The signal overlaps with methane, and researchers think that it is not yet possible to tell the two apart.

They did so by using computer models that simulated the physics and chemistry of both the molecule and the likely atmosphere on K2-18b. Those models suggested that there was no way to be sure that the finding actually showed the presence of dimethyl sulfide, or DMS.

But the findings may simply suggest that we have not found signs of life just yet, rather than not at all. Scientists are further examining the planet with other instruments, and will be able to definitively see whether that molecule exists there.

It will do so using an instrument that is better at detecting infrared wavelengths than the one that was used in the study last year.

The work is described in a new paper, ‘Biogenic sulfur gases as biosignatures on temperate sub-Neptune waterworlds’, published in The Astrophysical Journal Letters.