Self-Review: The Vocabulary of the Night Sky

In the first few lectures, we cover a number of rather abstract concepts. However, you are already familiar with much of the information presented, only from a different point of view. Take a look at the following questions and see if you can answer each one in turn. After thinking about the answer, place the mouse over the button and see if you are correct.

(Note: The following works with Internet Explorer 4.0 and later. If you are using Netscape as your browser, then the answers are displayed at all times. Obviously, this will make answering the questions much easier.)

1. Distance that light, moving at 300,000 km/s, travels in one year; equal to about 10 trillion kilometers.
   Answer    One Light Year
   
   

2. The Sun's family: planets, moons, minor planets.
   Answer    Solar System
   
   

3. Term for average distance of the Earth from the Sun, measured at 149,603,500 km.
   Answer    Astronomical Unit
   
   

4. The extremely large (100,000 light years in diameter) grouping of stars, gas and dust, all held together by mutual gravity. Our Sun is just one star of 100's of billions found here.
   Answer    Milky Way Galaxy
   
   

5. Term used to group the 30-40 galaxies existing within about 3-4 million light years of our galaxy:
   Answer    Local Group
   
   

6. Imaginary line dividing the eastern and western hemispheres of the sky, as seen from an observer's location.
   Answer    Meridian
   
   

7. The point on the celestial sphere directly over an observer's head (altitude = 90 degrees).
   Answer    Zenith
   
   

8. The place where the celestial sphere (sky) meets the Earth:
   Answer    Horizon
   
   

9. Point on the celestial sphere directly above the Earth's north pole.
   Answer    Celestial North Pole
   
   

10. Point on the celestial sphere directly above the Earth's south pole.
    Answer    South Celestial Pole
    
    

11. The projection of the Earth's equator onto the celestial sphere.
    Answer    Celestial Equator
    
    

12. A human grouping of stars into a recognizable pattern.
    Answer    Constellation
    
    

13. Time required for the constellations to complete one cycle around the sky and return to their starting points, as seen from a given point on Earth.
    Answer    One Year (365.24 days)
    
    

14. Period of time between the instant when the Sun is directly overhead (noon) to the next time it is directly overhead.
    Answer    One Day (Mean Solar Day = 24 hours)
    
    

15. Time needed for a star on the celestial sphere to make one complete "revolution" in the sky.
    Answer    23 hours 56 minutes
    
    

16. A Unit of angular measure. There are 360 of these in one complete circle.
    Answer    Degree
    
    

17. The twelve (really 13) constellations through which the Sun moves during the course of a year.
    Answer    Zodiac
    
    

18. Apparent path of the Sun, relative to the background stars, over the course of a year.
    Answer    Ecliptic
    
    

19. The science that studies the basic structure, origin, and evolution of the cosmos, the universe in which we live.
    Answer    Cosmology
    
    

20. True or False: the scheme of astrology is totally based upon scientific fact, and the results predicted are statistically significant in most, if not all, cases.
    Answer    False (If you missed this question, we need to talk!)