ISP 205, Section 3, Spring 1997, Hufnagel & Stein

Homework 2

Due: Tuesday 27 January 1997


                                        Name: ________________________


                                        Student Number: ______________

1. (5 Pts) Sketch the orbit of the Earth around the Sun as viewed from the outer planets. That is, use an edge-on perspective. Place the Earth in the proper position for winter in the northern hemisphere. Add a few arrows to show the direction the Earth is moving in its orbit, and a line through the Earth to represent its spin-axis. It's OK to not draw the Earth and Sun to scale.

2. (5 Pts) (a) Sketch the approximate relative positions of the Earth, Moon and Sun for a lunar eclipse, as viewed from above the North Pole of the Earth. (The relative sizes need not be to scale.)

(b) What phase is the Moon in? Full

3. (5 Pts) Suppose you are standing on the corner of Hagadorn Road and Grand River Avenue and you see the Moon, fairly high in the sky, to the south (down Hagadorn Road) just after sunset. What is the phase of the Moon? (Hint: All of these phase-of-the-Moon questions are easy once you figure out the relative positions of the Sun, Moon and Earth for each question. So first figure out what direction the Sun is at sunset.)

First Quarter

4. (4 Pts) (a) What constellation is Polaris in? Ursa Minor

(b) What constellation was Polaris in 100 years ago? Ursa Minor, Stars move only very slowly with respect to each other.

5. (3 Pts) Why is the heliocentric (Copernican) model of the Solar System superior to the geocentric (Ptolemaic) model?

(a) It is a simpler model, yet it explains all of the observations.
(b) It predicted that the inner planets would appear to have phases when viewed from the Earth, which was later found to be true.
(c) It predicted that the Earth itself was moving, which was later found to be true.
(d) The heliocentric model doesn't require the Earth to be at a unique position in the Universe.
(E) All of the above.

6. On the attached sky map for December, identify as many of the stars from the attached list of 16 brightest Northern Hemisphere stars as you can find by drawing a small circle around each and writing its name next to it. (1 point for each correct star, but minus 1/2 point for each incorrectly labeled star.) This is the same type of question, but for different months, which will be asked on all of your midterms and the final.

List of 16 Bright Northern Stars

December Sky Map with Stars labeled

A Reminder on Grading Policy

Your grade is determined by the percentage of total points you earn, not the total points. The points shown on each question tells you the weight we assign to each question when we calculate your percentage for each homework. Each homework counts the same toward your final grade.
Visions of the Universe
Beth Hufnagel's home page, email: hufnage4@pilot.msu.edu
Bob Stein's home page, email: steinr@pilot.msu.edu