【科技日报】寻找“地球2.0”

Core Viewpoint - The Chinese Academy of Sciences' National Space Science Center announced several space exploration satellite plans during the "14th Five-Year Plan" period, including a mission to search for Earth-like exoplanets, referred to as "Earth 2.0" [1] Group 1: Importance of Searching for "Earth 2.0" - The search for "Earth 2.0" is driven by human curiosity about the existence of life beyond Earth [2] - Finding "Earth 2.0" could provide a "backup home" for humanity, addressing existential threats such as resource depletion and global warming [2] - Researching Earth-like planets may help understand Earth's past and future, and answer philosophical questions about humanity's uniqueness in the universe [2] Group 2: Criteria for "Earth 2.0" - "Earth 2.0" must meet strict criteria regarding its physical properties, stellar environment, and habitability conditions [3] - The planet's radius should be between 0.8 to 1.25 times that of Earth, ensuring a solid surface and atmosphere [3] - It must orbit a sun-like star within the "habitable zone" to maintain liquid water on its surface [3] - A suitable atmosphere and a stable global magnetic field are essential for protecting life [3] Group 3: Current Discoveries in the Search for Earth-like Planets - The Kepler Space Telescope has discovered over 6,000 exoplanets, but none have been Earth-sized and within the habitable zone [4] - Significant milestones include the first confirmed exoplanets in 1992 and the discovery of the first Earth-sized rocky planet, Kepler-10b, in 2011 [4][5] - In 2017, a system with seven Earth-sized planets was confirmed, with several potentially having conditions for liquid water [5] - China's contributions include the discovery of a "super-Earth" in the habitable zone, which is ten times the mass of Earth [5]