There are many theories on the formation of Pluto. Some scientists theorize that Pluto was originally a distant asteroid or comet that got caught in the Sun's gravity. Another theory says that Pluto was an asteroid that wandered away from the asteroid belt between Mars and Jupiter. Still another theory is that Pluto was once a moon of Neptune. One of the more successful theories is that Pluto was formed at the birth of the solar system. It is thought that at that time there was a cloud of gas beyond the orbits of Jupiter and Saturn. As the cloud shrank, millions of small chunks formed. They might have been like the heads of comets, made
