How many planets in the universe can sustain life?

They are too numerous to count, but with the estimated millions to billions of planets, many of them are suitable. However, with the technology available to us today, it is not currently possible to move to another planet, so it is possible that we will move to a different planet at some point in the future.

Our best estimate as of right now is Titan, the largest moon of Saturn. Recent studies indicate that Titan may have liquid water beneath its surface, and it may even be in Alpha Centauri. The planet must be in the Goldilocks zone, which Titan is not. Where there is water, there is the greatest possibility of life.

Mars would have had liquid water and an atmosphere if we were born 3.8 billion years ago with the technology we have today.

That life exists on even one planet in the universe is an astronomical accident; the odds of achieving a functional protein by chance exceed the number of particles in the universe multiplied by the estimated time in the universe.

It is uncertain how many planets in the universe are capable of supporting life. Researchers are working hard to find exoplanets that are in the habitable zone, but exact counts are conjectural.