| A | B |
|---|
| Moon | Natural satelite that orbits a planet |
| Star | Glowing ball of hot gas that makes its own energy and light |
| Asteroid belt | Region between Mars and Jupiter where most asteroids orbit the sun |
| Planet | Large object in space that orbits a star such as the sun |
| Sunspots | Dark areas on the sun's surface that gives off less energy than the rest of the sun |
| Meteor | Brief streak of light seen when an asteroid enters the Earth's atmosphere and burns up |
| Greenhouse effect | Warming of the atmosphere because of trapped heat energy from the sun |
| Solar system | A star, such as the sun, and all of the objects that revolve around it in space |
| Comet | Ball of ice, rock, frozen gases, and dust that orbits the sun |
| Atmosphere | Envelope of gas surrounding an object in space |
| Meteorite | Piece of rock that hits the surface of a planet or moon after traveling through space |
| Asteroid | Rocky object, smaller than a planet, that orbits a star |
