| A | B |
|---|
| comet | a chunk of rock or dust in space |
| solar eclipse | when the moon's shadow hits the Earth |
| lunar eclipse | when the earth's shadow hits the moon |
| asteroids | chunks of rock in orbit too small to be planets |
| elliptical | the shape of earth's orbit |
| inertia | the tendency for a object in motion to stay in motion |
| rotation | refers to the Earth spinning on its axis |
| one year | the amount of time it takes for the Earth to revolve around the sun |
| moon phases | refers to the amount of the sunlit side of the moon seen from Earth |
| one month | the approximate time it takes for the moon to revolve around the earth |
| one million | the amount of Earths that could fit inside the sun |
| light-year | the distance light travels in a year |
| east | the sun appears to rise from this direction |
| west | the sun appears to set in this direction |
| tides | the rise and fall of water on Earth |
| heliocentric system | a sun-centered system of planets |
| geocentric system | Earth-centered system of planets |
| meteoroid | a chunk of rock that came from an asteroid or a comet |
| meteor | a meteoroid that has entered Earth's atmosphere |
| meteorite | a meteor that has made it to Earth's surface |
