If you see craggy chunks of rock out there in orbit, should we call it a moon? There's a lot to learn from the topography of moons provided they don't have weather systems that erase the record of their collisions. So things you can learn when you see moons around other planets is, wyl was it? Is it massive enough to have made it into a spherical shape? If it's craggy, it's probably a chunk broken off of some other larger thing that was a sphere in a collision. How about earth? How many craters have you seen on earth? A few it. But we're right next to the moon in in te in the stream