1. one point, from Lecture 1, involves finding information, observations, sketches, descriptions. NOTE: DO NOT DELAY IN STARTING THIS PROBLEM!

(a) .4 Change of Season. Hint: use the Lecture 1 Supplements. Other useful sources are newspapers or TV weather, a calendar, and a telephone directory map.
Find out when the fall equinox is this year. (.1)
Find out the times of sunrise and sunset for three days between now and September 17 and calculate the average change in the length of the day. (.1)
Find a convenient street which runs due east-west and observe where the sun rises or sets on two different days relative to east-west. Is it north or south? (.1)
How is it changing this month? (.1)
In you answer, you must cite all of your sources, give the dates and locations of your observations, make a sketch of where the sun was relative to due east or west, and show your calculations. I suggest a sketch with a vertical line as if it were a post at the end of the street you are looking down, labeled east or west. Draw where the sun was relative to that post, and label whether it is north or south of due east or west.

(b) .3 Phases of the Moon. Find out what the phases of the moon are between September 1 and September 17. (.1)
Observe the moon on two clear evenings or mornings. You'll have to figure out when to look if it isn't obvious. Sketch, label and describe what you see. (.2)
Include the date, time, a picture of the moon with white for visible and black for invisible, and where in the sky (angle and direction) it was. Use the same way to depict this as I used in lecture: an arc with east on the left and west on the right, so that the peak of the arc is the highest position of the moon in the southern sky. Start soon, so the weather won't foil you!

(c) .3 Sideview Orbit Picture. Draw a side view of the earth's position relative to the sun on June 21 and December 22. Label the sun, earth, date, and distance from sun to earth; (.2)
and draw the earth's axis of rotation carefully, with the northern hemisphere and the angle of the axis relative to the orbital plane labeled. (.1)

Revised September 1, 1997.