Abstract:
Are we alone? You often hear this question because the formation of a terrestrial planet had been, theoretically, considered difficult if not impossible. This was changed after the NASA Kepler and K2 missions found that rocky planets are ubiquitous. Afterwards, it has become popular to resolve the natal environment of rocky planets, the protoplanetary disks, and then investigate the planet-formation activities observationally/theoretically. Without a surprise, most of those studies concluded that the protoplanetary disks we resolved are efficiently forming rocky planets, which, however, yield planets that are too wet and too carbonaceous to compare with our own Earth. Are we not alone? This is the issue I have been tackling. In this talk, I will provide an overview of this research field and outline our contribution/destruction.