So far, we’ve discovered hundreds of exoplanets, planets outside our Solar System, and of those exoplanets we’ve found at least three that may be able to support life. But our search for extraterrestrials doesn’t have to go as far as other star systems. The odds of finding alien life right here in our Solar System are increasing.
Water is essential for life. You and I are made of about 60% water, yet water in liquid form is extremely rare. Even here on Earth, there isn’t as much as you might think, as illustrated by a recent image on Astronomy Picture of the Day (click here to see it). Liquid water is almost nonexistent in other parts of the Solar System.
Yet scientists have found evidence of liquid water on the surface Mars, melting from the polar ice caps during the warmer seasons. There’s evidence of subsurface oceans on Jupiter’s moon Europa and Saturn’s moon Enceladus. Now the Cassini spacecraft has reportedly found another subsurface ocean on Titan, one of Saturn’s other moons (click here for more information).
I don’t know if Titan has life, but if we keep finding sources of liquid water we are bound to find life somewhere. This life would probably be bacterial. There could also be some kind of fish. Or maybe one of these subsurface oceans supports a civilization of alien mermaids.