Name: ______Date: ______Period: ____

Unit 5 Exam Review: Astronomy

1. A light-year corresponds to ______

2. The universe is both

a.  expanding and cooling. c. shrinking and cooling.

b.  expanding and warming. d. shrinking and warming.

3. Our galaxy is a ______type of galaxy.

4. According to the current theory used to explain the origin of solar systems, the

planets in our solar system:

  1. Formed from the same nebular cloud as the Sun.
  2. Were captured into orbit by the Sun’s gravity.
  3. Formed by the fusion of hydrogen in their cores.
  4. Contain more mass than the Sun.

5.  When stars form, hydrogen atoms combine to form helium in a reaction called

______

6. Stars, solar systems, galaxies, and planet/moon systems are all held together by what

force? ______

7. An astronomer is studying the electromagnetic radiation from two different stars. He

finds the first star to have a peak wavelength near the blue end of the visible spectrum

and the second star to have a peak wavelength near the red end of the visible spectrum.

Based on this information, the astronomer will conclude that:

  1. The second star is hotter than the first.
  2. The first star is hotter than the second.
  3. Both stars are the same temperature.
  4. Nothing, you can not judge temperature from a star’s color.

8. Which of the categories of electromagnetic radiation has the most energy

and the highest frequency. ______

9. What substance protects us from most ultraviolet radiation? ______

10. Which event caused by solar flares is not dangerous? ______
______

11. What are planets that orbit in the inner solar system and have large cores made

of iron with rocky exteriors called? ______

12. Which planet is the largest? ______Which is the coldest? ______

13. The Earth has fewer visible craters than the Moon because

  1. Most of the craters are hidden by the oceans.
  2. The Moon has shielded Earth from most impacts.
  3. Craters has been destroyed by geological processes.
  4. Volcanic activity on the Earth has covered most of the craters.

14. Which of the following explanations is the most accepted by astrologists on how the

Earth-Moon system formed?

a. A planet-sized object collided with Earth and the debris accreted into the Moon.

b. The Moon was a passing planetoid that was captured by our gravity.

c. The rapidly spinning Earth ejected a molten piece from its center.

d. The Moon was built by intelligent aliens as an observational satellite.

15. The force that creates the ocean tides is:

  1. The gravitational attraction of the Moon.
  2. The gravitational attraction of the Sun.
  3. The gravitational attraction of the Moon and Sun.
  4. The rotation of the Earth.

16. If the entire Earth was suddenly and permanently covered with a layer of snow, the

albedo of the Earth would ______making the Earth a much ______place.

17. At what two lunar phases would a spring tide occur?

  1. 3rd quarter and 4th quarter c. full and 3rd quarter
  2. full and new d. new and 4th quarter

18. The Earth’s speed of rotation is: a. increasing b. decreasing

19. The coma of a comet is made of ______.

20. When a rock from space reaches a planet’s surface, it is called a

a.  meteoroid c. meteorite

b.  meteor d. meteorsphere

21. What size does an asteroid or comet have to be in order to cause major damage or a mass

extinction on Earth? ______