Astronomers from the University of Cambridge have made a groundbreaking discovery that could hint at life beyond Earth. They found strong signs of possible biological activity on a distant planet called K2-18b, located about 124 light-years away from us. This planet is not in our solar system and is about eight times larger than Earth.
Using the James Webb Space Telescope, the scientists observed K2-18b and detected chemical signatures in its atmosphere. These signatures include two gases, dimethyl sulphide (DMS) and dimethyl disulphide (DMDS), which on Earth are linked to biological processes, particularly from marine life like algae. The presence of these gases suggests that K2-18b might be rich in microbial life.
The planet was first identified in 2017 by Canadian astronomers using ground-based telescopes in Chile. It is classified as a “hycean planet,” which means it may have vast oceans that could support life. The recent findings were published in a study in the Astrophysical Journal Letters, marking a significant step in the search for extraterrestrial life.
Nikku Madhusudhan, a lead researcher, emphasized the importance of caution in interpreting these results. He stated that while this is a promising lead, it is not yet proof of life. The data has reached a statistical significance level known as “three-sigma,” meaning there is a very low chance that these observations occurred by random chance. However, to be classified as a confirmed discovery, the findings would need to reach a “five-sigma” level, which indicates an even lower probability of error.
Other scientists are urging a careful approach to these findings. Christopher Glein, a principal scientist at the Southwest Research Institute, noted that while the data is intriguing, it requires thorough verification by independent researchers. He mentioned that previous claims about K2-18b have not always held up under scrutiny.
Madhusudhan and his team plan to conduct further observations to strengthen their findings. They believe that additional data could help confirm whether the detected gases are indeed linked to biological processes. He pointed out that while the current evidence is compelling, it’s essential to remain open to other explanations.
The discovery of DMS and DMDS aligns with earlier observations from the James Webb Space Telescope, which had previously identified methane and carbon dioxide in K2-18b’s atmosphere. These carbon-based molecules were the first of their kind found in an exoplanet’s habitable zone.
Madhusudhan expressed hope that K2-18b could be a thriving world full of life, but he also acknowledged the need for more research. He mentioned that they would need to explore other possibilities and ensure that the signals they detected are robust.
In summary, while the findings from K2-18b are exciting and suggest the possibility of life, scientists stress the importance of further investigation to confirm these results. The search for life beyond Earth continues, with K2-18b now at the forefront of this quest.