Introducing the Solar System

Question 0

Astronomical Unit (AU)

Answer 0

A unit of distance equal to the average distance between Earth and the sun, about 150 million kilometers.

Question 1

Solar System

Answer 1

The system consisting of the sun and the planets and other objects that revolve around it.

Question 2

Planet

Answer 2

Must be round, orbit the sun, and have cleared out the region of the solar system along it orbit (this means it does not share that area of its orbit with any other objects)

Question 3

Dwarf Planet

Answer 3

An object that orbits the sun and has enough gravity to be spherical, but has not cleared the area of its orbit (this means other objects share its orbit)

Question 4

Asteroids

Answer 4

Small, mostly rocky bodies that orbit the sun

Question 5

Comets

Answer 5

Loose balls of ice and rock that usually have very long, narrow orbits

Question 6

Planetesimal

Answer 6

One of the small asteroid-like bodies that formed the building blocks of the planets