This is one consideration in terms of planetary habitability or the possibility of extraterrestrial life. He also discussed human geography and the planetary habitability of the Earth. Planetary habitability of red dwarf systems is subject to some debate. The conditions of habitability for natural satellites are similar to those of planetary habitability. They estimated how much further humans can go before planetary habitability is threatened. An understanding of planetary habitability begins with the host star. These finds expand the potential habitability of certain niches of other planets. Astrobiologist and physicist known for his contributions to the field of planetary habitability. The past flow of liquid water demonstrates the planet's potential for habitability. Stability, luminosity, and lifespan are all factors in stellar habitability. Low eccentricity is needed for habitability, especially advanced life. While stellar crowding proves disadvantageous to habitability, so too does extreme isolation. There is some speculation on the potential habitability of Ganymede's ocean. The EJSM/Laplace mission is planned to determine the habitability of these environments. Drainage systems are a crucial compromise between human habitability and a secure, sustainable watershed.