As one of the few places in the solar system other than Earth known to have an ocean, Europa has become one of the most fascinating worlds that we know of. This moon of Jupiter is small, but enticing – beneath its frozen surface of ice is a global ocean of water, making it a primary focus of study, especially in terms of the search for life elsewhere.
Exoplanets are now being discovered on a regular basis, including ones that may be potentially habitable. But when even the nearest ones are so far away compared to the planets in our own solar system, how could they be studied for possible signs of life? Is that even possible?
In the search for life elsewhere, the Earth is typically used as a standard against which other planets, or moons, are compared. Since our planet is teeming with seemingly countless life forms, it must represent the near-perfect, most ideal conditions for life to flourish, right? It would seem so, but new research is suggesting that may not be the case, that there may be other exoplanets in other solar systems which are even better suited for life than Earth is.
If you are searching for other inhabited worlds, almost any kind of star may do according to current findings, except perhaps for white dwarfs. As it turns out, planets orbiting these dying stars, as well as brown dwarfs, are probably very poor candidates for life.