Astronomy 110G-05:   Midterm Exam (Sample)
SHORT QUESTIONS       (5 × 2 = 10 points)
Please keep your answers brief, and to the point. For multiple choice questions, chose and circle one and only one answer.

Is the "dark side of the Moon" always in the dark, and why?











What are 2 observations, possible with the naked eye, which contradicted the Ptolmeic model?
      [a]





      [b]










The Terrestrial planets in our solar system that have substantial atmospheres are:
      [a] the Moon and Mercury
      [b] Mercury, Venus, and the Earth
      [c] Mars, Venus, and the Earth
      [d] Mars, Jupiter, and the Earth

The more __________ an object is, the further back in time we look when we observe it.
      [a] bright
      [b] faint
      [c] nearby
      [d] distant























SOLAR FLUX       (6 × 5 = 30 points)
Please draw a box around your final answer for each question. We will give partial credit, so show your work and attempt every question.

Recall that the average distance between the Sun and Neptune is 30 AU.
How much sunlight per unit area falls on Neptune, relative to Earth?






Recall that the radius of the Earth is RE = 1.25 × 104 kilometers, and the radius of Neptune is
RN = 2.50 × 104 kilometers.
How large is the area of the silhoutte of Earth (the area of the disk on the sky), in square kilometers?









How large is the area of the silhoutte of Neptune, in square kilometers?









How much total sunlight falls on Neptune, relative to Earth?









Where would you place Neptune in the solar system, in order for it to receive the same amount of total sunlight that the Earth receives, in A.U.?









What planet lies closest to that position?

Useful Numbers
1 centimeter = 0.01 meters
1 kilometer = 1,000 meters
1 A.U. = 1.50 × 1011 meters
1 year = 365 days
1 year = 3.15 × 10 7 seconds