Download ASTR 1105: Dr

ASTR 1105
Dr. Shawn T. Cruzen
SHORT ANSWER
MIDTERM EXAM (125 points)
MAY 2012
Name_______________________________
5 points each (Questions 1-7)
1.
Describe in detail the formation of the Jovian planets, emphasizing how their formation differs
from the terrestrials.
2.
Describe as many physical similarities AND differences between the Moon and Mercury as you
can.
3.
Describe six properties of objects in space that can be measured using spectroscopy.
4.
Other than the Solar Nebula theory, describe two early models of cosmogony. Explain why these
models fell out of favor with astronomers.
5.
Describe the factors that determine whether a planet will have a significant magnetic field? Why
are magnetic fields on planets important to us as humans that might visit other worlds? Which of
the eight planets in our solar system do NOT have substantial magnetic fields? For each one,
explain why.
6.
Define and describe the scientific method.
7.
State completely each of Newton’s three laws of motion. Give an example of each one from
everyday life.
SHORT ESSAY 10 points each USE THE BACK SIDE IF NECESSARY! (Questions 8-11)
8.
Describe the telescopic discoveries made by Galileo explaining how EACH one supported the
Copernican model and contradicted the Aristotelian model.
9.
Describe Solar Nebula theory and the formation of our solar system in as much detail as you can.
10.
State completely each of Kepler's Three Laws of Planetary Motion. Draw a diagram illustrating
each one.
11.
Label the diagram below with the appropriate names of the lunar phases (as viewed from Earth) for
each of the eight positions of the Moon shown. Then, in a small box next to each phase, sketch a
drawing of how the Moon would appear if photographed from Earth during that phase. Label all of
the sketches with the directions East (E) and West (W).
The Moon and Its Orbit
The Sun’s Rays
The Earth
The Sun
NUMERICAL PROBLEMS: SHOW ALL OF YOUR WORK!! 5 points each
12.
The orbital eccentricity of the planet Neptune, which has a nearly circular orbit, is e = 0.0097. The
radius of its orbit is approximately 30.1 AU. (a) What is the major axis of Neptune's orbit in
Astronomical Units (AU)? (b) What is the distance between the center of the Sun and the second
focus of Neptune’s orbit in kilometers? (c) Is this distance greater or less than the distance
between the Earth and the Sun? Remember: 1 AU = 1.5 x 1011 meters and e = (Distance Between
Foci)(Major Axis)
13.
The orbit of Comet Cruzen (ha!) has a period of 1000 years.
a) Use Kepler's 3rd Law in the form P12 P22 = R13 R23 to find the semimajor axis of the
comet's orbit in Astronomical Units (AU).
b) Convert the answer into meters. (Hint: 1 AU = 1.5 x 10 8 km)
14.
Two planets orbit a distant star. One revolves at a distance of 12AU and one at a distance of 3AU.
The planet at 3AU from the star has a period of 72,000 hours.
(a) Is the star more or less massive than our Sun? Why?
(b) What is the period of the 12AU planet?
15.
Use Newton’s Law of Universal Gravitation to calculate what your weight would be on the
surfaces of all eight planets in our solar system plus the Moon and the dwarf planet Pluto. (Jovian
planets obviously don’t have surfaces, so use their given diameters from the textbook.) (Use
reverse side or extra paper)
16.
(a) The focal length of a refracting telescope is 275 cm and it has a 25-mm eyepiece. What is the
magnification this instrument?
(b) If the diameter of a refracting telescope is increased by 50%, what is the change in the light
gathering power?
(c) For a wavelength of 6500 Angstroms, how much better is the resolving power of a 200-cm
telescope than a 75-cm telescope.
m = (F.L. Telescope)  (F.L. Eyepiece)
Surface Area = r2
R.P. = 2 x 10-3 (/d)
17.
WILDCARD QUESTION: Describe any additional topic covered in this class in as much detail
as you can. Use the back of the exam. (Should be at least a full page long.) 25 Points