CHES: An astrometry mission hunting for nearby habitable planets

The Closeby Habitable Exoplanet Survey (CHES), a proposed space-borne mission to detect Earth-like planets orbiting 100 nearby solar-type stars (～10 pc or approximately 32 light years from the sun) via micro-arcsecond relative astrometry, is currently being considered by the Chinese Academy of Sciences as a possible space mission for future launch (Figure 1). The discovery of Earth-like planets (or Earth twins, planets with an orbit, mass, and environment similar to Earth) in the habitable zones around nearby solar-type stars will be another “giant leap for mankind” and help us begin to answer essential scientific questions such as “Are we alone in the universe?”, “Is Earth unique?”, and “How do planets become the cradle of life?” Finding such planets could even enable future human visits and identify new habitable places to live.