Will humans hear back from aliens on K2-18b? Not for at least 248 years

The hunt for alien life in the universe has been going on for years. Now we finally have a planet where someone likely lives, although whether it is intelligent life or mere microbes is not known. Scientists at the University of Cambridge, led by Dr Nikku Madhusudhan, announced that K2-18b, a planet orbiting a red dwarf star 124 light-years away, has all the characteristics exhibited by life.

However, before humans rush to make contact with life on this planet, it is important that caution is exercised. Experts have long warned that trying to find aliens and then reaching out to them might bring devastating consequences for humanity. They suggest learning about the civilisation thoroughly before firing up relations with them.

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Former Indian Space Research Organisation (ISRO) chief S Somanath previously warned that alien civilisations in the universe are likely at different stages of technological advancements. A civilisation that is 1,000 years ahead of us might be interacting with the universe in ways human beings cannot perceive. 

But Somanath isn't interested in contacting aliens. "I would be happy to never be in contact with aliens," he said on a podcast. 

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He feels they might have different genomic and protein structures than we do, which might be dangerous to life on Earth. 

Similar concerns have been raised by British physicist and science writer Mark Buchanan, who fears that contacting aliens may result in "the end of all life on Earth".

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He told MailOnline that the alien civilisation might not be interested in responding to signals sent by humans, or they could be so powerful that they might enslave humans.

Professor Avi Loeb, a theoretical physicist at Harvard University, raises another dilemma humans face while contacting aliens. 

"This planet, K2-18b is 124 light years away. If we send a communication signal towards it right now, the earliest time for us to receive a response at the speed of light is 248 years from now, in the year 2273."

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This means humans would have to come up with a better plan if they wish to effectively contact aliens.

Using data from the James Webb Space Telescope (JWST), astronomers concluded that the planet is 2.6 times larger than Earth. The space telescope detected water vapour in its atmosphere, making it the first exoplanet in the habitable zone where water is present. The team said there is a 99.7 per cent likelihood that it hosts biological life.

K2-18b's atmosphere contains dimethyl sulfide (DMS) and dimethyl disulphide (DMDS). These biosignatures are also found on Earth at about one part per billion. On K2-18b, it is present in 10 parts per million on K2-18b.