There are 7 moons in the solar system that are larger than the planet pluto.

Pluto is the 9th planet in the solar system and it made up of mostly ice and light rocks. It has a radius of about 1100KM.

Pluto was actually calculated to exist before it was seen visually. Percival Lowell saw there were errors in neptunes orbit (as described by keplars laws) and calculated the existence of the Planet.

Once pluto was found scientists were dumfounded. Lowell had determined Pluto to be 7-8 Earth masses, when in fact Earth is much larger than Pluto.

Coincidentally Lowells calculations were incorrect and Pluto caused very minimal librations in Neptunes orbit.

very interesting..

ok think how far away pluto is.. think how small it is.. think we could missing another planet??

Thats actually why there is a large debate whether to actually classify pluto as a planet.

There are thousands of TNO (trans neptune objects) that are also known as Plutinos. Though none of them even approach the size of pluto, they are made up of the same stuff and take similar orbits in the solar system.