1. Earth & Space Vocabulary

2. Astronomy  The study of the moon, stars, and other objects in space

3. Rotation  The spinning motion of a planet on its axis

4. Axis  An imaginary line that passes through Earth’s center and the North and South poles, about which Earth rotates

5. Revolution  The movement of an object around another object

6. Orbit  The path of an object as it revolves around another object in space

7. Solstice  The two days of the year on which the sun reaches its greatest distance north or south of the equator

8. Equinox  The two days of the year on which neither hemisphere is tilted toward or away from the sun

9. Gravity  The attractive force between objects; strength depends on masses of objects and distance between them

10. Inertia  The tendency of an object to resist any change in its motion

11. Phase  One of the different apparent shapes of the moon as seen from Earth

12. Waxing  When the Moon changes from new to full (growing)

13. Waning  When the Moon changes from full to new (shrinking)

14. Lunar Eclipse  The blocking of sunlight to the moon that occurs when Earth is directly between the sun and the moon

15. Solar Eclipse  The blocking of sunlight to Earth that occurs when the moon is directly between the sun and Earth

16. Tide  The periodic rise and fall of the level of water in the ocean

17. Meteoroids  A chunk of rock or dust in space

18. Crater  A large round pit caused by the impact of a meteoroid

19. Solar System  the Sun, its eight planets, & other objects that orbit the Sun

20. Astronomical Unit  is about 150 million km, the mean distance from Earth to the Sun

21. Meteorites  fragments of space material that land on Earth’s surface

22. Constellations  groups of stars that form patterns in the sky

23. Galaxy  group of stars, gas, & dust held together by gravity

24. Comet  large body of frozen ice and rock that travels toward the center of the solar system in an extreme orbit