Astronomy 110 PRINT Name   __________________________
Fall 2005   Section 006  

Homework 3 : Finding the Moon

(Due Thursday, Sep 15, 2005)

This is supposed to be a picture of part of the sky looking roughly westwards. It shows a full moon on the horizon and two planets in the sky.

Are the Moon and planets rising or setting?_____________

If you were to draw the Sun, would it be in the picture?__________


What time of day is it? (circle the correct answer.)

   Dawn      Morning      Noon      Afternoon      Sunset      Evening      Midnight  


What is the angle between the Moon and the Sun?______________

The Moon rises about 50 minutes later each night. On the diagram, sketch in roughly where you think the Moon will be a day later, at the same time. Assume the lower of the two planets is about 10 degrees above the horizon. (Hint: How many degrees does the Moon move across the sky in a day?)


Which two planets CAN'T these be?____________________________


Draw the rough position of the ecliptic on the diagram.

How did you know where to draw?

Is it likely that either or both of these planets is in retrograde motion at this time? ________

Reason :

Suppose there is a very bright star near the upper planet when you see the Moon and planets as in the diagram and suppose you note very carefully the positions of the planet and the bright star relative to other nearby stars and also their angles above the horizon. Now suppose you look again exactly 24 hours later by your (perfect) watch. Would you expect the position of the bright star to have changed

relative to other nearby stars? ________


relative to the horizon? ________


relative to the planet? ________