| A | B |
|---|
| rotation | spinning of Earth on its axis |
| revolution | movement of one object around another |
| solar eclipse | occurs when a new moon blocks your view of the sun |
| lunar eclipse | occurs when Earth is directly between a full moon and the sun |
| spring tides | Earth, moon, and sun in straight lines producing greatest difference in tides |
| neap tides | Earth, moon, and sun are at right angles producing the least difference in tides |
| gravity | force that attracts all objects toward each other |
| nonrenewable resource | items like fossil fuels that take hundreds of millions of years to form |
| solar energy | energy from the sun |
| energy conservation | reducing energy use |
| insulation | layer of material that traps air to block transfer of heat between a layers of a building |
| spiral galaxy | appear to have a bulge in the middle and arms that spiral outward |
| big bang theory | says the universe formed in an instant billions of years ago from an explosion |
| heliocentric model | earth and other planets revolve around the sun |
| asteroid belt | between mars and jupiter where asteroids revolve around the sun |
| meteroid | chunk of rock or dust in space |
| meteor | streak of light in the sky when a meteroid enters Earth's atmosphere |
