Name_________________________ 

ASTR220 Quiz #1 (12 pts.) 

(Multiple Choise = 1 pt.; Short Answer = 2 pts.) 

Choose the best answer to each of the multiple choice questions and
circle the corresponding capital letter on this sheet. Write your
answers to the short answer questions in the space provided.

1.   The Oort Cloud is 
        A. the source of comets. 
        B. the source of rocky asteroids. 
        C. the source of the satellites of Jupiter. 
        D. another name for the clouds of Venus. 

2.   A meteor shower such as we have every August is caused by 
        A. a large asteroid breaking up as it approaches Earch. 
        B. a swarm of particles that orbits the Moon. The Earth's gravity 
           disturbs them so that they fall into our atmosphere. 
        C. the Earth passing through the orbit of an old comet. 
        D. a swarm of particles that orbits the Earth. The Moon's gravity 
           disturbs them so that they fall into our atmosphere. 

3.  (1 pt.) Express the distance to Neptune (4.5 billion km) in
    scientific notation.





















4.   Which planet has a surface very much like that of our Moon? 
        A. Venus. 
        B. Mercury. 
        C. Jupiter. 
        D. Mars. 
        E. Callisto. 

5.   The fact that some asteroids are rocky while others are metallic 
     (iron-rich) is explained by 
        A. the Sun heating their surfaces and vaporizing the rock from some 
           of them. 
        B. their forming near Jupiter, whose immense gravity drew the iron 
           outward. 
        C. their being fragments of larger objects that had melted and 
           formed iron cores through differentiation. 
        D. The statement is false. Asteroids are essentially all alike in 
           their composition. 

6.   The maria of the Moon are thought to have originated as 
        A. bodies of water which are now dried up. 
        B. lava flows from huge volcanoes. 
        C. areas eroded by wind before the Moon lost its atmosphere. 
        D. lava flows that flooded giant impact craters. 

7.   Give a short history of what happened to Comet Shoemaker Levy 9, 
     starting from when it was first captured around Jupiter. At what point 
     was it discovered, and by whom? 



















8.   As imaged by Voyager, Jupiter's moon Io had no impact craters due to 
        A. its thin crust which is broken on impact, then refills with water 
           and freezes. 
        B. its volcanic activity. 
        C. its liquid surface. 
        D. its tremendous atmosphere. 

9.   Describe how comet tails are formed. Draw a picture showing the Sun, the 
     comet's orbit, and the comet's gas and dust tails. Label everything! 


















10. The close up images of asteroids taken by the Galileo probe on its 
     journey to Jupiter revealed that these asteroids had 
        A. cratered surfaces. 
        B. atmospheres. 
        C. spherical shapes. 
        D. volcanic activity.