How many planets are there in the Universe?
We don't know. We are not able to see the whole Universe, but in the part we can see it is estimated there could be 10,000,000,000,000,000,000,000,000 planets!
So far we know of eight planets in our own solar system. Another 4,000 outside our solar system (called "exoplanets") are considered "confirmed", and thousands more are waiting for more observations before we can be sure if they are.