Is it a no-doubter that alien life exists? It depends on who you ask. But do humans have proof of extraterrestrial life? That’s less complicated.
So far, no hard evidence that life exists beyond planet Earth has come to light.
But that might soon change.
Signs of biological life?
Experts and the internet alike are roiling over potential findings from the James Webb Space Telescope (JWST). In a recent CNBC interview, UK astronaut Tim Peake spoke about the possibility we’re not alone.
“Potentially, the James Webb telescope may have already found [alien life]… it’s just that they don’t want to release or confirm those results until they can be entirely sure,” he said. “But we found a planet that seems to be giving off strong signals of biological life.”
Peake’s tease piggybacked on a prediction last year by UK astrophysicist Becky Smethurst. She claimed in a YouTube video that “we are going to get a paper that claims to have strong evidence for a biosignature in an exoplanet’s atmosphere very, very soon.”
Smethurst then walked it back.
So turns out something I said in a YouTube video has been jumped on by UFO enthusiasts & then bizarrely the @spectator
I said that in 2024 we could see a claim of a biosignature found in the atmosphere of an exoplanet with JWST. This was just an enthusiastic and hopeful guess. https://t.co/RH3EFR04iK
— Dr Becky Smethurst (@drbecky_) January 17, 2024
So, what’s going on here?
ArsTechnica’s Eric Berger sought to set the record straight. He sourced Knicole Colon, a deputy project scientist for exoplanet science on the JWST.
“JWST has not found definitive evidence of life on an exoplanet,” she said. “It is anticipated that JWST observations may lead to the initial identification of potential biosignatures that could make habitability more or less likely for a given exoplanet. Future missions will be needed to conclusively establish the habitability of an exoplanet.”
Where should we look
So…if we think it’s there, and we think we know how we’re going to find it — where should we be paying attention?
One juicy target is K2-18 b, an exoplanet 8.6 times as massive as Earth situated 120 light years away. NASA has acknowledged there’s evidence it may be a “Hycean” exoplanet, meaning it hosts water oceans and a hydrogen-rich atmosphere. Astronomers also know these planets as “sub-Neptunes,” because some of their characteristics match up with the familiar eighth planet.
Hycean planet, artist’s rendering. Image: Wiki Commons
Nikku Madhusudhan, an astronomer at the University of Cambridge, led a study that explored the viability of K2-18 b for biological life.
“Our findings underscore the importance of considering diverse habitable environments in the search for life elsewhere,” he told NASA. “Traditionally, the search for life on exoplanets has focused primarily on smaller rocky planets, but the larger Hycean worlds are significantly more conducive to atmospheric observations.”
They’re common, too. Another member of Madhusudhan’s team called sub-Neptunes “the most common type of planet known so far in the galaxy.” And they create big enough signatures on the JWST’s sensors that it can see them relatively freely.
But even if these oceanic worlds with hydrogen atmospheres are plentiful and promising, the signs of life on them might not look like much.
Smethurst — the astrophysicist who last year predicted an oncoming study claiming the discovery of extraterrestrial life — poured cold water on the hype. If only by adjusting potential expectations to reality.
“The leap from ‘potential biosignature’ to full-on ‘aliens’ is ridiculous,” Smethurst said, per Futurism. “By biosignature, we’re talking tiny molecules in the atmosphere of an exoplanet…not aliens on a rocky planet.”
