I'm not sure, but I think simple life is abundant in our galaxy and the rest of the universe, and there may even be simple life on Ganymede, Europa and Mars.

The primitive forms of complex life are probably uncommon (one in every 100,000 planets), but because of the size of the universe, are on many planets in the universe.

More evolved forms of complex life are rare (on about one in every 1,000,000 planets), but still, because of the enormous size of the universe, evolved complex life exists on many planets.

Intelligent life is probably very rare in the universe, on about 1-5 planets per large galaxy (like the Milky Way and Andromeda galaxies).

But what exactly is intelligent life? Are crows, dolphins, and orangutans intelligent? Are ants intelligent? Are incirrina, which have amazing eyesight and complex brains?


Humans are an extremely destructive species, so I imagine if there were advanced, truly intelligent beings who are aware of us, they'd wipe up out before we go out to any other inhabited worlds.