If I recall, Velikovsky surmised that the asteroid belt contains the remains of a busted planet.
Or maybe that was Zechariah Sitkin.
Anyway, they are very entertaining writers full of wonderful thought experiments and scenarios, but last I heard there was no evidence whatsoever that the asteroids were ever parts of a large planet; and there is some evidence that they were NOT.
And if they were not, the odds on Ceres having sprouted life are mighty low.