| A | B |
|---|
| the system of nine planets and many smaller objects that orbit the Sun | solar system |
| second smallest planet and closest to the Sun | Mercury |
| the second planet from the sun which is similar in size and mass to Earth | Venus |
| the third planet from the Sun | Earth |
| the average distance from Earth to the Sun (150 million km) | astronomical unit |
| the fourth planet from the sun - known as the red planet | Mars |
| the fifth planet from the sun and the largest | Jupiter |
| a giant, high-pressure gas storm on Jupiter | Great Red Spot |
| the second-largest planet and the sixth planet from the Sun | Saturn |
| the seventh planet from the Sun | Uranus |
| usually the eighth planet from the Sun | Neptune |
| considered to be the ninth and smallest planet | Pluto |
| a mass of frozen gases, dust, and rock particles that often develops a bright tail when it passes near the sun and is acted on by solar winds | comet |
| a cloud of comets surrounding the solar system beyond Pluto's orbit | Oort Cloud |
| a meteoroid that enters Earth's atmosphere and burns up as it falls | meteor |
| a meteor that does not completely burn up in Earth's atmosphere and strikes Earth's surface | meteorite |
| a piece of rock similar to the material that formed into the planets | asteroid |
| a portion of the universe and all of its components, processes, and interactions | system |
| an instrument that is sent to space to gather information and send it back to Earth | space probe |
| a natural satellite of a planet that is held in its orbit around the planet by the planet's gravitational pull | moon |
| a nearly circular depression in a planet, moon, or asteroid that formed when an object from space hit its surface | crater |
