Paris: Astronomers announced Thursday that despite skepticism from other scientists, they have discovered “cues” of the most promising potential life on planets outside our solar system.
The scientific community debated whether the planet K2-18b, which has 124 light-years in the Leo sign, could be a marine world that can host microbial life.
Using the James Webb space telescope, a team of British researchers discovered signs of two chemicals in the Earth’s atmosphere, long considered “biological signatures” that indicate the lives of aliens.
On Earth, chemicals dimethyl sulfides (DMS) and dimethyl disulfides are produced only by life, mainly microscopic marine algae, called phytoplankton.
The researchers stressed caution, saying more observations are needed to confirm these findings, and they did not announce the confirmation of the findings.
The impact could be huge, says Nikku Madhusudhan, astrophysicist at the University of Cambridge and lead author of the study.
“What we are currently finding is a hint of possible biological activities outside the solar system,” he told reporters.
“Frankly, I think this is the closest we are to see the function we can attribute to life.” But what the outside experts pointed out about the controversy that the outside aliens had previously discovered, adding that these chemicals could have been created through the unknown, which means that they have nothing to do with life.
Of the approximately 6,000 exoplanets discovered so far, K2-18b has more than eight times the mass, and about 2.5 times as it orbits its stars in habitable or “Goldilocks” regions.
This means it cannot be too hot or too cold to have liquid water, the most important ingredient in life.
Telescopes observe exoplanets so far away when they are in front of stars, allowing astronomers to analyze how molecules prevent light from passing through the atmosphere.
In 2023, Weber telescope detected methane and carbon dioxide in the K2-18b atmosphere, and for the first time this carbon-based molecule was detected on exoplanets in habitable zones.
It also detects weak signals from chemical DM, causing astronomers to turn Webb to Earth again a year ago, this time using infrared instruments to detect different wavelengths of light.
They found much more signs of chemicals, although still below the statistically significant “five Sigma” threshold for scientists seeking such discoveries.
Even if the result is confirmed, it does not necessarily mean that the earth is the home of life.
Last year, scientists found traces of DMS on comets, suggesting that it can be produced in a non-organic manner, perhaps not a “bio signature.”
However, the chemical concentrations observed on K2-18b appear to be thousands of times stronger than those on Earth, which may indicate biological origins.
K2-18B has long been considered the main candidate for the “Sea Planet”, a larger ocean world than the Earth, with rich hydrogen.
These planets are not expected to be home to smart alien life, but are similar to microorganisms in Earth’s oceans billions of years ago.
Some studies question whether the currently proposed seafood planet is too close to the star to support liquid water, including K2-18B, orbiting its star every 33 days.
Raymond Pierrehumbert, a professor of planetary physics at Oxford University, conducted a separate study showing that K2-18B is too hot for life.
He told AFP that if the earth does have water, it would be “hell-like heat” and uninhabitable, adding that the sea of lava is more reasonable.
Sara Seager, a professor of planetary science at MIT, called for patience, which suggests that previous claims about water vapor in the K2-18b atmosphere proved to be a different kind of natural gas.
Madhusudhan estimates that Webber’s time only takes 16 to 24 hours to reach the five sigma threshold, which could happen in the next few years.
Stephen Burgess, a statistician at the University of Cambridge, explained that the current three sigmas are comparable to the chance of flipping a coin and getting the same result each time.
He said the five Sigmas will get results after 20 flips, meaning “we can be very sure that this kind of observation is not just an opportunity.”
Even outside of K2-18B, Webb and future telescopes can allow humans to discover life outside our hometown earlier than people think, Madhusudhan said.
“This could be the tipping point, and suddenly, whether we are alone in the universe is the basic question we can answer,” he said.
