In a new study, astrophysicists at Harvard University claim that if some form of alien life does indeed have the ability to move from planet to planet — much like a virus — (a process called panspermia), it would spread in a predictable pattern that we could potentially detect it.
The ancient Earth was a hostile environment marked by unpredictable climate and oxygen-deprived air over 3 billion years ago. Until this week, scientists believed that life forms came into existence, and started using Earth’s nitrogen, around 2 billion years ago. But the new research from the University of Washington changes all these previous theories.
If life on Earth has taught us anything, it is that where you find liquid water, you generally find life. Looking at our solar system, we now have good reason to conclude that at least a handful of moons — Europa, Ganymede, Callisto, Enceladus, Titan, and possibly Triton — may harbor vast bodies of liquid water beneath their icy shells.