How many planets in the universe can sustain life?
Can't be shortened as it is already short
They cannot be counted
But, as there are estimatedly millions to billions of planets, many of them are suitable
But with the tech we have today, it's not possible now to shift to another planet.
So, one day may come in which we'll shift to another planet
Our best guess by now is Saturn's largest moon Titan.... new researches suggest that there is liquid water under the surface of Titan... Also It could be in Alpha Centauri.. The planet has to be in Goldilocks zone... Which Titan isn't in.. but Where there is Water.. there is the best chance of organisms living...
If we were born 3.8 billion year ago with the same tech we have today.. there'd be Mars with an atmosphere and liquid water
Quite possibly none
The odds of achieving a functional protein by random chance exceeds the number of particles in the universe multiplied by the estimated time in the universe. That life exists on even one planet in the universe is an astronomical accident.