NAME: ______DATE: ______

Planets and Other Objects in Space

Study Guide

Please know the following vocabulary:

_____ 1. Star- Burning sphere of gases

_____2. Comet- Small mass of ice and dust that orbits the sun

_____ 3. telescope - Instrument used to observe a distant object

_____ 4. Axis- Imaginary line the Earth rotates around

_____ 5. Satellite- An object that moves around another

_____ 6. Planet- Large object that moves around a star

_____7. outer planets- Jupiter, Saturn, Uranus and Neptune

_____ 8. solar system- Central star and the objects that move around it

_____ 9. space probe- Vehicle sent to explore space

_____ 10. gas giants- Large spheres made mostly of gases

_____ 11. Orbit- Path an object takes when revolving around another object

_____ 12. Asteroids- Objects that move between Mars and Jupiter

_____13. Rotation- Spinning movement of Earth

_____ 14. Phases- Changes in apparent shape of the moon

_____ 15. Revolution- Movement of Earth around the sun

_____ 16. inner planets- Planets between the asteroid belt and the sun

17. How are rings around planets formed ?

rock, ice crystals, and dust

18. What are orbits like for planets that are close to the sun?

orbit faster than the outer planets

19. What has a space probe found that could prove liquid water may have once existed on

Mars?

sedimentary rocks- which are formed by water.

20. What does Earth have that other planets do not?

liquid water

21. What is the source of almost all the energy in our solar system?

the sun

22. How long does the moon’s cycle of phases take to complete?

About 28 days

23. What causes Earth’s seasons?

The Earth’s revolution around the sun and the tilt of its axis

24. Why do we see phases of the moon?

As the moon revolves around the Earth, different amounts of sunlight is reflected on the moon. The lit part that we see is a moon phase.

25. What does Earth’s orbit look like?

An oval or elliptical path. (Like an egg.)