Title: Why is life only possible on Earth? - Quora
Headings: Why is life only possible on Earth?
Why is life only possible on Earth?
Anonymous

Content: We don't yet know for certain that there isn't. Right now, life as we know it would not survive anywhere except Earth or Mars, and possibly Europa (in our solar system). Life requires liquid water. Europa (one of Jupiters moons) has a muck of mud some hundreds of kilometers below the ice that has water in it, and there might be life there. Equatorial regions of Mars get above freezing for parts of the year, and while the Martian atmosphere is too thin to sustain liquid water on the surface, the pressure is great enough underground, and muddy slurries of landslides from subsurface water have been observed. Earth of course has oceans of the stuff. It all has to do with pressure and temperature for water. Now, whether there is life there or not, that we aren't sure of. I believe that we cannot be the only planet in the Universe that has life, because there is a billion billion galaxy in the Universe, each containing a hundred million billion stars with hundred million billion habitable zones and a gazillion objects in the habitable zone; Who are we to say that none of them contain water AND life?