Long ago, it's said that there used to be a planet in between Mars and Jupiter that is now the asteroid belt. Are there any records of this time? Did there used to be a sailor scout for that planet too?
Actually that statement is not entirely accurate. To begin with, there actually isn’t that much stuff in the asteroid belt. If you were to take the entire asteroid belt and form it into a single mass, it would only be about 4% of the mass of our Moon. Assuming a similar density, it would be smaller than Pluto’s moon Charon.
If you arrange all the asteroids in order of their average distance from the Sun, you find they aren’t evenly distributed. Instead you find a bunch, then a gap, then a bunch more, then another gap, and so on. These gaps in the asteroid belt are known as Kirkwood gaps, and they occur at distances where an orbit would be in resonance with the orbit of Jupiter.
Jupiter’s gravity is so strong, that it makes asteroid orbits within the Kirkwood gaps unstable. It’s these gaps that prevented a single planetary body from forming in that region. So, because of Jupiter, asteroids formed into families of debris, rather than a single planetary body