The 3 attributes of a planet:
1. is in orbit around the Sun
2. is nearly round
3. has cleared its orbit
It is called a 'proto-planet', this is the 'before-planet'-stage; It has gathered enough mass to form a large gravity field and cause a spherical shape.
They are called space junk, and there are about 20,000 now that are large enough to be tracked.
The fictional planet Tralfamadore is the moon of a large planet called Tran.
A "Gas Giant" planet.
A Satellite. There are man made satellites (equipment or stations put into orbit by a rocket) and natural satellites, which are called moons if large enough.
That is called the planet's orbit.
Ore
That is called a planet.That is called a planet.That is called a planet.That is called a planet.
they would of found out about asteroids because when the dinosaurs were extinct a massive comet hit earth and it destroyed it and the reason planet earth was created again was because a large enough rock formed into a planet and if the rock is not large enough then it wont form into a planet
Strangely enough, the Romans had a large part in it.
A subcontinent?
That is commonly called a gas giant.