| A | B |
|---|
| astronaut | a person who travels in space |
| satellite | an object that moves around Earth and sends messages down to Earth |
| telescope | a tool that makes objects that are very far away look much bigger and closer |
| space shuttle | a space craft that can be reused to carry people into space and back to Earth |
| solar system | a group of objects in space, the Sun and all of the planets and moons, that go together |
| universe | all of space, the planets, stars and galaxies |
| Milky Way galaxy | he group of stars, planets, dust and gas that our solar system is in |
| Sun | the star in the center of our solar system that gives us heat and light |
| gravity | a force that weighs things down |
| orbit | a path an object in space takes around another object |
| revolve | to move around an object |
| axis | an imaginary line that goes through the center of the Earth |
| rotate | to spin |
| one year | 365 1/4 days |
| 24 hours | 1 day |
| seasons | are caused by the tilt of the Earth as it revolves around the sun |
| Rocky planets | Mercury, Venus, Earth, and Mars |
| Mercury | is the smallest planet and is closest to the Sun |
| Venus | is the second planet from the Sun and is the hottest planet |
| Earth | is the third planet from the Sun and is 29% land and 71% ocean |
| atmosphere | a layer of gases that surround a planet |
| Mars | the fourth planet from the Sun and is the Red planet |
| gas giants | planets made up of gas, ice and dust |
| Jupiter | the largest of all the planets |
| Saturn | has 7 rings |
| Uranus | the blue-green planet that rotates on its side |
| Neptune | has the strongest winds and is the last planet |
| Great Red Spot | a storm on Jupiter |
| asteroid | pieces of rock and metal |
| meteor | small pieces of metal or rock from an asteroid |
| star | a giant ball of hot gas |
| constellations | patterns formed by stars |
