Introducing The Solar System Flashcards
Astronomical unit
A unit of distance equal to the average distance between Earth and the sun, about 150 million kilometers.
Solar system
Our solar system consists of the sun, the planets, their moons, and variety of smaller objects
Planet
An object that orbits a star, is large enough to have become rounded by its own gravity, and has cleared the area of 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. (TGIS MEANS OTHER OBJECTS ALSO SHARE ITS ORBIT.)
Asteroids
One of the rocky objects revolving around the sun that are too small and numerous to be considered planets.
Comets
A loose collection of ice and dust that orbits the sun, typically in a long, narrow orbit.
Planetesimal
One of the small asteroid-like bodies that formed the building blocks of the planets.