Multiple lines of evidence point to past flows of water across the Martian surface, but conditions on the planet now preclude the existence of liquid water. (scientificamerican.com)
Studies of anomalies in water's behavior have indicated the existence of liquid water with both lower and higher densities than this standard. (sciencedaily.com)
«We have 54 planets in the habitable zone of their stars,» Borucki says, referring to the temperate orbital zone around a star that would allow for the existence of liquid water on a planet. (scientificamerican.com)