| A | B |
|---|
| atmosphere | the blanket of air and gases that surround the Earth |
| orbit | the path of any object in space that revolves around another objectin space |
| climate | weather conditions of a certain area, including temperature, rainfall, and wind |
| constellation | a group of stars that make a pattern or shape |
| galaxy | stars are in gigantic groups called |
| gravity | a non-contact force that pulls objects toward each other |
| planet | a large body of rocks or gases that do not give off light, and that revolves, or travels, around any star |
| axis | an imaginary line around which Earth spins |
| revolution | one complete trip around the sun |
| rotation | one complete spin on an axis |
| seasons | changes in the weather during the year caused by the Earth's tilt as it revolves around the sun |
| solar system | the Sun, the nine planets and their moons, and other objects that revolve around the Sun |
| star | a massive ball of hot gases that produces its own light |
| tilt | slanted |
| universe | everything that exists - plantes, out solar system, and space |
| lunar phases | the way the Moon looks because of the amount of the lit side of the Moon that can be seen from Earth at the same time (take about 29 1/2 days) |
| equator | the imaginary line that separates the north and south halves of Earth |
| moon | the natural satellite that orbits around Earth |
| sun | our star; a huge ball of hot, glowing gasses |
| solar eclipse | then the Moon moves directly between the Earth and the Sun, making the Sun appear to turn black |
