I have mentioned Europa and Enceladus, moons of Jupiter and Saturn, as being among the most intriguing bodies in the solar system, since their liquid oceans create the potential that life could exist or survive there. Now we know that the dwarf planet Ceres, the largest object in the asteroid belt between Mars and Jupiter, also has an extensive reservoir of brine beneath the surface.
Any would be a fascinating target for scientific exporation, though with the crucial caveat that it would require better planetary protection techniques to prevent them from being colonized by organisms from Earth which might take over in any habitable niche and which could even exterminate extraterrestrial life. We now believe that despite efforts to sterilize them spacecraft on the moon and Mars likely harbour viable life forms from Earth. That may not pose much of a risk in a hostile environs with a thin or absent atmosphere and merciless radiation, but it must be among the central concerns for any mission which will visit a body with liquid water.
Bacteria From Earth Can Survive In Space and Could Endure the Trip To Mars, Says Study
—
DNA Damage and Survival Time Course of Deinococcal Cell Pellets During 3 Years of Exposure to Outer Space
Hubble Captures Crisp New Image of Jupiter and Europa | ESA/Hubble