| 报告摘要： |
An innovative Chinese space mission, the Earth 2.0 (ET) mission, is being developed to combine the transit and microlensing methods together to search for Earth-sized exoplanets in the Galaxy, including the most precious ones---Earth 2.0s, i.e., habitable Earth-sized (0.8-1.25 Earth radii) planets orbiting solar-type stars, cold and free-floating low-mass planets. ET’s 6 transit telescopes will monitor an FoV of 500 square degrees (covering the Kepler field) continuously for at least four years and generate a huge database containing high-cadence and ultra-high photometry precision light curves of ~1.2 million FGKM dwarfs. With such a high-value database, many unsolved issues in the exoplanet field and even stellar sciences will be well addressed. Besides looking for Earth 2.0s and constraining its occurrence rate, ET will be dedicated to map a much wider radius-period diagram of terrestrial-like exoplanets than ever and reveal how it depends on the stellar properties and environments. With the 4-yr legacy data of Kepler, ET will catch additional components in a multi-planet system, e.g. cold Giant, cold sub-Earths, exomoons, exorings, and even exocomets. Are exomoons and exocomets common in a planet system? What’s the favorite number of planets in a multi-planet system? What’s the most common orbital configuration of planetary systems? With these new data, ET will deepen our understanding of how unique our Solar system is and how multi-planet systems evolve. In addition to exoplanet sciences, ET’s time series data will also benefit the studies in asteroseismology, archeology in the Galaxy, time-domain astrophysics, and black hole science. In this talk, I’ll briefly introduce the scientific background of the ET project and the associated technology challenges. |
