Introducing The Solar System Flashcards
Astronomical unit(AU)
A unit of distance equal to the average distance between Earth and the sun, about 150 million kilometers.
Solar system
The system consisting of the sun and the planets and other objects that revolve around it.
Planet
Must be round, orbit the sun, and have cleared out the region of the solar system along its orbit.
(This means it does not share the area of its orbit with any other objects).
Dwarf Planet
An object that orbits the sun and is spherical, but has not cleared the area of its orbit.
(This means other objects also share its orbit).
Asteroids
Small, mostly rocky bodies that orbit the sun.
Comets
Loose balls of ice and rock that usually have very long, narrow orbits.
Planetesimal
One of the small asteroid-like bodies that formed the building blocks of the planets.