Astronomers Discover Possible Signs of Life on Distant Planet
Scientists have recently identified tentative evidence suggesting that a planet orbiting a distant star might host life. This finding comes from a study by a team at Cambridge University, who analyzed the atmosphere of a planet known as K2-18b using Nasa’s James Webb Space Telescope (JWST). They detected molecules in the planet’s atmosphere that, on Earth, are produced by simple life forms.
Although this discovery is promising, the team emphasizes the need for more data to confirm their findings. The researchers, led by Prof Nikku Madhusudhan, believe that the evidence suggesting life could be confirmed within the next one to two years.
K2-18b, which is two and a half times the size of Earth and located about seven hundred trillion miles away, is being studied for its atmospheric composition. Thanks to the powerful capabilities of JWST, scientists can analyze the light passing through the planet’s atmosphere to determine its chemical makeup. The team identified signs of chemicals that could indicate life, specifically dimethyl sulphide (DMS) and dimethyl disulphide (DMDS), which on Earth are produced by marine organisms.
The amount of these gases present in K2-18b’s atmosphere is much higher than on Earth, leading Prof Madhusudhan to suggest that if the association with life holds true, then the planet could be teeming with life. He also posits that confirming life on K2-18b could imply that life is widespread in the galaxy.
However, the current findings are not conclusive. To definitively claim the presence of life, the results must reach a five-sigma level of confidence, indicating a 99.99999% certainty. The current results are at a three-sigma level. Despite this, it is a significant improvement over the team’s previous findings of 68% certainty.
Other experts, like Prof Catherine Heymans and Prof Oliver Shorttle, point out that detecting these molecules doesn’t necessarily confirm the presence of life, as there could be other geological processes on the planet producing them. They advocate for further research to understand the origin and context of these gas emissions.
This discovery has reignited the scientific debate about the nature of K2-18b, with some researchers suggesting alternative explanations for the data that do not involve life. Dr Nicolas Wogan from Nasa’s Ames Research Center proposes that K2-18b might be a mini-gas giant with no surface, which challenges the life-supporting planet theory.
Despite these debates, Prof Madhusudhan remains optimistic that this could be a turning point in the quest to discover life beyond Earth. He believes that in the coming years, scientists might look back at this time as the moment when the possibility of a living universe became reality. The study’s findings are published in The Astrophysical Journal Letters, marking a significant step toward answering humanity’s long-standing question about whether we are alone in the universe.
Source: https://www.bbc.com/news/articles/c39jj9vkr34o
