Alien Life in the Solar System

Phosphene | ESI | Tidal Heating | Sub-surface ocean | Water vapour geysers

Only Earth sits in the habitable zone around the Sun where conditions are right for liquid water to exist on the surface: a prime requisite for life to develop. Although it is too cold and dry today, Mars has evidence of water-generated features on its surface and is believed to have been habitable in the past. Recently, astrobiologists have taken a more flexible view in the search for extraterrestrial life and this has provided other contenders in our solar system where the prospect of life developing is being given serious consideration.

Out of all the factors it takes for a planet or moon to support life, the presence of water has always been considered one of the most vital and the prime candidates may have a significant amount locked away in sub-surface oceans.