Astrobiology is a research field studying on what kind of space organisms (S-organisms) are living under what kind of life system or genetic system and on consequences which an Earth organism (E-organism) is suffered from environments in space when the organism is placed in there, and so on. In fact, explorations of planets in Solar system, as Mars, and their satellites of Jupiter and Saturn, as Europa, Enceladus, and Titan, have been carried out by NASA to find out some traces of life. In Japan, it was widely informed through newspapers, and so on, at the time when Japanese spacecrafts, Hayabusa and Hayabusa 2, which were designed to bring asteroid samples back to Earth, launched to asteroids, “Itokawa” and “Kaguya,” that a clue for solving the origin of life might be brought.