热点问答｜“最有力证据”能否证明系外生命存在

Core Insights - The international team led by Cambridge University announced the discovery of what is considered the "strongest evidence" for potential life beyond Earth in the atmosphere of the exoplanet K2-18b, located approximately 124 light-years away [1][2] - This discovery has sparked significant interest in the scientific community, although it has also faced skepticism regarding the actual existence of life [1][3] Group 1: Discovery Details - K2-18b has a mass about 8.6 times that of Earth and a volume approximately 2.6 times larger [2] - The research team utilized instruments on the James Webb Space Telescope to analyze the atmosphere of K2-18b, identifying chemical signatures of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), which on Earth are produced solely through biological activity [2][3] - This marks the first detection of carbon-based molecules in the atmosphere of an exoplanet located in the habitable zone, aligning with predictions of a water-covered world beneath a hydrogen-rich atmosphere [3] Group 2: Skepticism and Challenges - There are ongoing questions about whether K2-18b has water or a surface suitable for life, with some analyses suggesting it may not be habitable [4] - The existence of DMS and DMDS in the atmosphere remains uncertain, with some researchers arguing that the signals could be statistical noise rather than biological markers [4][6] - Even if the signals are confirmed, there are concerns that these molecules could also be produced through non-biological processes, necessitating further investigation [4][6] Group 3: Future Research Directions - The lead researcher expressed cautious optimism and emphasized the need for more data before claiming the discovery of extraterrestrial life [7] - Future observations using the James Webb Space Telescope are planned to confirm the findings, and independent validation from multiple research teams is deemed essential [7] - The importance of studying planets like K2-18b is highlighted, regardless of whether the current findings are validated, as they push the boundaries of exoplanet research [7]