How many solar systems are there in Milkyway, our galaxy?
Well, the actual number out there is not known. As everyone’s said, Milky Way is estimated to have upwards of 200 billion stars in it. We don’t know what percentage of stars have planets orbiting them, but I personally assume that it would be a high percentage. It just seems pretty reasonable to me that forming stars wouldn’t be perfect in slurping up their entire stellar disks while condensing. Now whether or not the remaining material forms planets, and whether or not their orbits are stable remains to be seen. Currently, we can’t see with enough precision. When we investigate a star for planets and don’t find any, we can’t say that there are none – just none found. When we can observe distant stars with enough precision to say with confidence that we would not miss any planets with something like 90+% uncertainty, then we would begin to say which stars definitely do not have planets. We have found over 200 extrasolar planets to date. I’m not sure how many of them are in unique syste
