Asteroid Belts Could Show Us Where Intelligent Life Is Hiding
If we want to find intelligent life elsewhere in the universe, it might be wise to look for stars with asteroid belts similar the one in our own Solar System. According to the theory of punctuated equilibrium, evolution goes faster and further when life has to make rapid changes to survive new environments — and few things have as dramatic an effect on the environment as an asteroid impact. If humans evolved thanks to asteroid impacts, intelligent life might need an asteroid belt like our own to provide just the right number of periodic hits to spur evolution on. Only a fraction of current exoplanet systems have these characteristics, meaning places like our own Solar System — and intelligent aliens — might be less common than we previously thought.
Astronomers Rebecca Martin and Mario Livio have hypothesised that the location of the Solar System’s asteroid belt — between Jupiter and Mars — is not an accident, and actually necessary for life. As the Solar System formed, the gravitational forces between Jupiter and the Sun would have pulled and stretched clumps of dust and planetoids in the inner Solar System. The asteroid belt lies on the so-called “snow line” — fragile materials like ice will stay frozen further out, but closer in they will melt and fall apart.