"It's half Pluto's size and 12% of its mass, which makes it much more similar to the Earth's moon than any other moon in the solar system." ...

Find out about the solar system and learn the order of the planets with a song in this video ... and dwarf planets such as Pluto.

Our solar system has eight planets but in recent years, astronomers have theorised there could well be a ninth planet that's hiding in our solar system we've not been able to see yet.

Both systems include a moon that is a large fraction of the size of the main body, unlike other moons in the solar system. The scenario also could support Pluto’s active geology and possible ...