Sophisticated life forms are relative newcomers on Earth compared to bacteria and archaea. They arrived later because the Earth proved to be a healthy environment over a long period of time. Because the environment of other planets is more primitive, life on other planets (if it exists) may be primitive. If not, then life would have developed the ability to withstand otherworldly environments as well as finding material for food. We might have to imagine what such creatures would be like.

Primitive life forms may have an easier time in a harsh environment. All life will leave behind certain signs that it has been there. Scientists recently thought that they had found some of these signs on a Martian meteorite, but it turned out to be untrue. No concrete evidence of life anywhere other than life has been found.

Here we present a look an the environments of some places in the solar system; Mercury, Venus, Mars, Jupiter, Io, Europa, Saturn, Titan, other moons, Uranus, Neptune, Triton, Pluto, comets, and interstellar space.