| A | B |
|---|
| Tide | the regular rise and fall of the sea level surface |
| Maria | smooth, flat plains on the moon that appear as dark patches |
| Equinox | when both hemispheres have 12 hours of daylight and 12 hours of darkness |
| Orbit | path an object takes when it revolves around another object |
| Asteroid | a rocky space object that revolves around the sun, mostly in a region between Mars and Jupiter |
| Lithosphere | Earth's rigid outer layer |
| Convection zone | area of the sun where energy is transferred by flowing gases |
| Gravity | universal force that attracts, or pulls all objects that have toward one another |
| Solar eclipse | when the earth moves into moons shadow |
| Solstice | 2 times of the year when the sun is closest and furthest from the earth's equator |
| Star | A huge ball of very hot glowing gases |
| Solar System | the sun and all of its satelites |
| craters | we know that the moon ha been hit by many meteorites because of its numerous |
| lunar eclipse | occurs when the moon moves into the Earth's shadow |
| moon | is an example of a natural satalite |
| By observing the changing locations of sunspots | scientists discovered that the sun rotates |
| Earth's atmosphere | provides protection from the sun's dangerous ray and meteorites |
| northern hemisphere | experiences warmer weather from June to September because arth's tilt causes it to recieve more solar energy |
| Earth completes one revolution in | one year |
| The amount of gravitational force between two objects depends on | their distance apart and their mass |
| The pull of the suns gravity and a planets forward motion | causes the planet to stay in orbit |
| milky way | described as a spiral galaxy |
| 1 day | the time it takes the earth to rotate once on its axis |
| nuclear fusion | reaction from the energy given off from the sun |
| core | where nuclear fusion occurs |
| 3 layers of the sun's atmosphere | photosphere chromosphere corona |
