MIDTERM AST1002 EXAM #1 February 17, 2010
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c = 3 x 108 m/s
F = GmM/r
P2y = A3AU
c = f; = c/f; f = c/
2
v = d/t; t = d/v; d = v*t
LGP = D2
= 0.25 /D ( in m, D in m!)
Power = T4
( = 5.67 x 108 W/m2K4)
T = 2,900,000/max
E = mc2
(T in K, max in nm)
v = c /
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The following questions are taken from the Lecture Materials as discussed in the Review.
1) What planet has the Prof. mentioned rising in the East after sunset on several occasions?
a. Mars
b. Neptune
c. Venus
d. Mercury
2) The Tropics of Cancer and Capricorn refer to
a. The West and East longitude sections of the Equator respectively.
b. The two latitudes where the sun is directly overhead at the solstices.
c. The latitudes above which there will be midnight suns at the poles in the
respective summers.
3) Which of the following constellations/star clusters actually do have stars that are close together
in both distance and angular separation as seen from Earth?
a. The Pleiades
b. Cassiopea
c. Orion
4) What model for the solar system was shown to be correct due to Galileos observation of the
phases of Venus?
a. The Ptolemaic Epicycle model
b. The heliocentric model
c. The Aristotelian perfect circle model
d. The Firmament model.
5) How can an astronomer figure out the mass of a planet?
a. From the distance and the radius.
b. From the temperature and the color
c. From the period of its orbit around the sun (or another star)
d. From the period and orbital radius of its moon (if it has one)
6) The temperature of a star is about 5800 K. What is the predominant wavelength of the light it
emits? (Choose the answer that is closest to the exact answer.)
a. About 10 meters.
b. About 10 nm (nanometers)
c. About 500 nm (nanometers)
d. About 1 centimeter.
7) What is the best way to increase the angular resolution in the design of a telescope?
a. Use a glass lens instead of a mirror.
b. Use a higher magnification eyepiece
c. Use a larger diameter primary lens.
8) If an astronomer projects the image of a star from a backyard telescope onto a screen and it makes a
blurry image, what is being considered?
a. The seeing disk of the star due to atmospheric conditions.
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b. The motion of the star due to more than one exoplanets orbiting it.
c. The effects of redactive optics.
9) The James Watt Space Telescope has what special feature.
a. It will orbit between the Sun and Mercury
b. It will orbit Pluto
c. It will be the first gamma ray telescope to orbit another star (Alpha Centauri)
d. It will orbit with the same period as the Earth, but in a more distant orbit
located at the L2 Lagrangian point.
10) The Spitzer, Chandra, and Compton space telescopes look at light, respectively, in the
a. Infrared, X-ray, and gamma ray wavelengths
b. Visible, X-ray, and radio wavelengths
c. Radio, Visible, and Infrared wavelengths
d. Infrared, Visible, and Ultraviolet wavelengths.
11) What kinds of asteroid types, orbits, structures, descriptions, etc. are there?
a. Trojan (Langrangian orbit)
b. Earth crossing orbit
c. Gaps in belt
d. Kuiper belt orbit
e. Only a,b, and c above.
12) The sizes of exoplanets that can be detected most easily from the star wobble are
a. About the size of the moon
b. About the size of our solar system (at least 40 AU in diameter).
c. About the size of Jupiter
d. Generally smaller than Pluto.
13) The current theory for the Moons formation is that
a. It is the result of an indirect collision between two objects that were nearly
the size of the Earth and the Moon
b. It is the result of an asteroid capture like Phobos and Deimos that orbit Mars.
c. It is the result of a giant asteroid hitting the side of the earth and knocking a
piece out into orbit. The hole left is where the pacific ocean is now.
14) It is possible to measure the variations in the Earths magnetic field
a. by using a Cavendish balance, as shown in class a week ago.
b. by the irregularities in the tides.
c. by looking at magnetized lava flows from regions of tectonic plate
separation.
15) For the dynamo effect to exist in a planet, there should be:
a. A solid iron core
b. A liquid metallic core and a reasonable rotation rate.
c. A solid metallic core and no rotation rate
d. A magnetic crust on the planets surface.
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16) The NASA spacecraft that will soon go into the same orbit as Mercury around the Sun is
called
a. Passenger Pigeon
b. Apollo 17
c. Voyager 17
d. Messenger
e. JWST III
The following questions are general questions from materials in the Lecture, Book, HWs
Quizzes, and/or previous exams.
17) How often can we see the far side of the Moon from Earth with the naked eye?
a. Once a month during the new moon.
b. about 12 times a year.
c. never.
18) Orion is now appearing near the Zenith at night. Where should you look to see it?
a. Near Polaris
b. Southern horizon
c. Eastern horizon
d. Almost straight up.
19) For a star with the coordinates Right Ascension = 0 hours, Declination = +90 degrees, where
should you look?
a. Towards the South pole
b. Towards Hawaii
c. Towards Russia
d. Towards the North Pole
e. Anywhere along the Equator.
20) Just after sunset, an astronomer said that he could see Mercury just above the horizon in the
West, and Venus was also seen very close to Mercury, but a bit higher above the western
horizon by a few degrees. Comment on this observation.
a. This happens only once every 26,000 years due to the Earths precession rate.
b. This observation is in agreement with the known orbital distances of the terrestrial
planets.
c. The object the astronomer is calling Venus is definitely not Venus.
d. It is impossible to see both Venus and Mercury at the same time.
e. The object the astronomer is calling Mercury is definitely not Mercury.
21) Why is sidereal day shorter than the solar day?
a. The speed of the stars is faster than the speed of the Earths orbit.
b. Due to the Earths orbit, it takes longer for the earth to rotate back to the same
position with respect to the Sun than to the same position with respect to the stars.
c. The Moons gravity speeds up the solar time.
d. It isnt. The sidereal day is exactly 2.7 times the solar day.
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22) Name two things that exhibit retrograde behavior.
a. The orbit of Mars as seen from Earth, and the rotation direction of Venus
b. The orbit of Mars and the orbit of Mercury as seen from Earth.
c. The orbit of Mars as seen from Earth, and the orbital direction of the asteroid belt.
d. The rotation direction of the Sun, and the rotation direction of the Moon.
23) The Galilean Satellites are
a) the 4 larger moons of Jupiter.
b) the 2 asteroid-like moons of Mars.
c) the objects that sit at the two Lagrangian points in Jupiters orbit at plus and minus 60 degrees.
d) the 4 tiny moons of Venus first seen by Galileo.
24) Everybody knows that the bigger a visible light telescope mirror is, the better, but at some point
a single piece of glass is just too heavy. What can astronomers do?
a) Build a huge mirror out of smaller segmented mirrors like the Keck.
b) Build smaller twin or quadruplet mirror telescopes and link them together as an
interferometer like the VLT.
c) Both answers a) and b) above.
d) None of the above.
25) The angular distance between two radio sources in a binary system is on average 0.001
arcseconds. What is the smallest radio telescope primary lens diameter you can use to tell you
that you are seeing two distinct radio sources? (Assume the light is about 0.6 m in
wavelength.)
a) 100 m
b) 25 m
c) 15 m
d) 1.7 m
e) 150 m
26) When the seeing is bad for ground based astronomy, what technology an allows improved
resolution in observations?
a) Switching to refractive, rather that reflective, primary lens systems.
b) Switching to either the x-ray or gamma ray part of the spectrum.
c) Retroactive optics.
d) Adaptive optics.
e) Only a) and b) above.
27) How large is the effective diameter of the VLBA radio telescope?
a) The size of the mountain caldera in Puerto Rico
b) The size of New Mexico
c) The size of Manhattan
d) The size of the Northern Hemisphere
28) We know the relative distances between the Earth, Sun and Moon vary since
a) Meteor showers dont come every two weeks.
b) We do not have eclipses every two weeks.
c) We observe both total and annular solar eclipses.
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d) None of the above.
29) Can you measure the gravitational force between two objects in the laboratory?
a) No. You cannot detect the attraction between even heavy objects of normal size. You
need Earth sized objects.
b) Sure. If you put two lead balls on a table one centimeter apart, they will slam into each
other.
c) Sort of. When you are a passenger in one of two heavy cars that pass each other closely
on the highway, you can feel the gravitational tug of one on the other.
d) Sure. Just use a Cavendish balance.
e) Nope. Not even a Lagrangian balance is sensitive enough.
30) If the Earths orbit around the sun were what it is now, how long in present earth years
would the new earth year be?
a) About 9 years
b) About 2 years
c) About 1 year there is no change with distance.
d) About 0.35 years.
31)
A new star is born in our Galaxy with a visual magnitude of 3 (negative 3).
a) It is an unusually bright star, even brighter that Sirius
b) It cant be seen with the naked eye.
c) It can only be seen with the aid of a telescope.
d) It can only be seen with the Hubble telescope.
32) The star in problem 31 above emits light predominantly at a wavelength of 290 nm. What is
the temperature of the star?
a. 2900 K
b. 841 million K
c. 5800 K
d. 10,000 K.
33) A politician from Florida is trying to get a $100,000,000 earmark from Washington to build a
gamma ray telescope near the football stadium for FSU.
a. This is a good idea since gamma rays can penetrate the often cloudy and humid
atmospheric conditions in Tallahassee.
b. It might be better just to transform Doak stadium into a big radio telescope dish,
and maybe less expensive!
c. This is a good idea since it is very easy to focus gamma rays into very high resolution
images using only glass refractive lenses.
34) The recent earthquake in Haiti was the result of
a. Global climate change
b. The relative motion of the North American and Caribbean plates.
c. Tidal forces due to the unusual lining up of the Moon, Earth and Sun.
d. Recent giant changes in the Earths magnetic field direction
35)
During an Equinox on Saturn, due to the sunlight,
a. The rings cast the thinnest shadow on the planet.
b. The rings cast the thickest shadow on the planet.
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c. The rings melt and become invisible.
36) Our solar system is the result of
a. The gravitational collapse of a cloud of gas and dust that contained the
remnants of previously exploded stars.
b. The explosion of a rapidly spinning star.
c. The capture of asteroids from interstellar space by the Sun.
d. The collision of two stars about the size of the Sun.
37) Which planet or planets or moons have the largest magnetic field?
a. Mars
b. Mercury
c. Venus
d. Earth
38) Which planet or planets or moons have carbon dioxide atmospheres?
a. The Moon and Venus.
b. Venus and Mars
c. Mercury and the Moon
d. Phobos and Deimos
39) Which planet or planets or moons have tertiary atmospheres?
a. Mars
b. Mercury
c. Venus
d. Earth
e. The Moon
40) Which planet or planets or moons have strange or very special axis rotation behavior?
a. Mars and Earth
b. Venus and Mercury and the Moon
c. Venus and Mars
d. Demos, Phobos, and Mars
41) Which planet or planets or moons have no tilt to their rotation axes?
a. Mars and Earth
b. Venus and Mars
c. Venus and Mercury
d. Mars and Mercury
42) The largest volcanic feature in the solar system is
a. The Caloris basin on Mercury
b. Olympus Mons on Mars
c. The Barringer crater in Arizona
d. The Copernicus crater on the Moon.
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The following questions are from the reading assignment in the book (pages 187-189).
43) In a primary atmosphere, one might expect a planet to have
a. Hydrogen and helium gas
b. Oxygen and nitrogen gas
c. Carbon dioxide, sulfur dioxide, and water vapor
44) In a secondary atmosphere, one might expect a planet to have
a. Hydrogen and helium gas
b. Oxygen and nitrogen gas
c. Carbon dioxide, sulfur dioxide, and water vapor
45) On Earth, nitrogen originated from
a. The beginnings of life
b. Radioactive decay
c. The result of the Suns ultraviolet radiation breaking down chemical bonds.
46) If all of the carbon dioxide dissolved in Earths crust were released,
a. The atmosphere would be very similar to that of Mercury
b. The atmosphere would be very similar to that of Venus
c. The temperature on the surface of earth would decrease by at least 100 K.
47) In 2008 the Venus Express team
a. Detected small amounts of hydrogen steadily leaking into space from
Venuss upper atmosphere.
b. The first strong evidence that Venus really does have a dynamo effect and a
magnetosphere.
c. The first strong evidence for a significant concentration of oxygen in Venuss
troposphere, possible enough to sustain life in microbes.
48) In the reverse greenhouse effect
a. Lower temperatures allow more carbon dioxide to be absorbed by a
planets surface.
b. The planet heats up as the ozone hole increases.
c. Higher temperatures blow the carbon dioxide into space.
49) One of the reasons why Marss atmosphere is so different from Earths is
a. Mars cooled down more rapidly.
b. Mars has two moons, not just one.
c. Its volcanic activity was much greater that on Earth.
d. Mars spins ten times faster on its axis than Earth does.
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The following questions are from the Extra Credit reading assignment (Charbonneau et al.,
Nature, Vol. 462, 891(2009).
50) The topic of the paper is
a. The discovery of a Kuiper belt object 10 times the size of Pluto
b. The discovery of another star orbiting our solar system
c. The discovery of a giant planet in the Cygnus-X solar structure.
d. The discovery of a super-earth sized extrasolar planet
e. The first gamma ray burst from our Milky Way center.
51) The subject of this investigation is called
a. Cygnus-X GP1
b. M31-b
c. USC 567-Lb
d. GC 1783c
e. GJ 1214b
52) The main method of detection shown in Figure 1 of the paper involved
a. Photometric (transit) light curve data.
b. Gamma ray spectra (Doppler shifted)
c. The wobble of the parent star center of mass (radial velocity)
d. Periodic infrared emissions over a period of 10 years.
e. Gravitational lensing of companion star light.
53) The main feature of Figure 2 of the paper involved
a. Photometric (transit) light curve data.
b. Gamma ray spectra (Doppler shifted)
c. The wobble of the parent star center of mass (radial velocity)
d. Periodic infrared emissions over a period of 10 years.
e. Gravitational lensing of companion star light.
54) The size of the subject of this investigation as shown in Figure 3 of the paper
a. Smaller than Earth
b. Larger than Earth, but smaller than Neptune
c. Larger than Neptune, but smaller than Jupiter
d. Much larger than Jupiter
e. About the size of Mars
55) One very interesting conclusion of this investigation is that the subject
a. has a liquid surface mostly composed of water and a solid hydrogen core
b. is the smallest neutron star found to date.
c. is larger and hotter than the parent star.
d. proves beyond a doubt that there is no planet like Earth in terms of atmosphere
or size anywhere in the Milky way
e. It has a solid core mostly composed of water and a hydrogen-helium
envelope.
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