ASTRO 120 Sample Exam 1) If a planet has a reasonably strong magnetic field, we know that a. It is made entirely of iron b. There is liquid nitrogen below the surface c. It can harbor life d. It has a core of conducting material, probably in liquid form e. All of the above 2) Consider the following hypothetical situation: A spacecraft lands on a moon of one of the planets. The moon has a smooth surface resembling that of the lunar Mare. The rocks on the surface are found to be 4.2 billion years old. Why would such a finding be highly unusual? a. Such rocks are far older than any on the Earth s moon b. The Mare rocks on the Earth s moon are much older than 4.2 billion years c. If the surface is that old, it should be heavily cratered d. There should not be rocks on Mare e. The rocks cannot be that old, since the Solar System is younger than that 3) What is the altitude of the Sun at the meridian on the Vernal Equinox in Ames? a. 0 b. 30 c. 23.5 d. 48 e. 71.5 4) Kepler s third law implies that a. Planets closer to the Sun move faster b. A planet on an elliptical orbit moves fastest when closest to the Sun c. A planet on an elliptical orbit moves slowest when closest to the Sun d. Planets move at constant speed on elliptical orbits e. The semi-major axis of an elliptical orbit increases when the planet moves fast 5) Which rocky planet rotates the fastest? a. Mercury b. Venus c. Earth d. The Moon e. Mars
6) The four Galilean moons around Jupiter are a. All made entirely of rock b. Made of primarily hydrogen and helium gas just like Jupiter c. A mixture of rock and ice, with the ice fraction increasing with distance from Jupiter d. A mixture of rock and ice, with the rock fraction increasing with distance from Jupiter e. Made entirely of ice 7) Which two properties are most important in determining the surface temperature of a planet? a. Internal temperature and atmosphere b. Size and chemical composition c. Size and distance from the Sun d. Distance from the Sun and atmosphere e. Size and atmosphere 8) The Greenhouse effect in a planetary atmosphere is: a. When ultraviolet light from space passes through the damaged ozone layer of the Earth it causes massive heating of the planet b. When infrared (heat) radiation from the Sun is trapped by clouds in the upper atmosphere, warming the atmosphere from the top down c. When infrared radiation from the Sun is absorbed by the Earth, and then the Earth radiates this back into space d. When a giant glass house is placed over the planet to keep it warm and protected from the vacuum of space e. When sunlight passes through the atmosphere of a planet and warms the planet. The resulting heat radiation (infrared) is trapped by an atmosphere which does not allow transmission of the radiation 9) Which of the following objects in our Solar System has the strongest magnetic field? a. Earth b. Pluto c. Venus d. Neptune e. Jupiter
10) What two chemical elements make up most of Jupiter s mass? a. Hydrogen and helium b. Oxygen and nitrogen c. Iron and silicon d. Potassium and argon e. Carbon and argon 11) Why does Venus appear featureless when viewed through a telescope? a. It has a very thick cloud layer b. It has prominent dust storms c. Its atmosphere is so hot that shimmering distorts the image d. Its surface reflects sunlight so well that it seems featureless e. It is shy and so never reveals its bare surface 12) Compared to the lunar highlands (the terrae), the lunar maria are a. Smoother and older b. Hotter and damper c. More cratered and older d. Smoother and younger e. More cratered and younger 13) The principal constituent of the atmosphere of Mars is a. Hydrogen b. Nitrogen c. Oxygen d. Carbon dioxide e. Methane 14) What is significant of the Roche distance? a. The satellites of all the planets are located within this distance from their planets b. If an orbiting body comes within this distance to its planet, tidal forces may break it apart c. It is the distance from the surface of a planet to the upper atmosphere d. It is the radial measure of the size of a planet s core e. The Earth s distance to the Sun is equal to the Roche distance
15) The main asteroid belt lies between the orbits of which of the following planets? a. Mars and Earth b. Mercury and Venus c. Neptune and Uranus d. Jupiter and Saturn e. Mars and Jupiter 16) The most abundant gas in the Earth s atmosphere is, and the second most abundant is. (fill in the gaps) a. Carbon Dioxide, Water Vapor b. Hydrogen, Helium c. Nitrogen, Water Vapor d. Oxygen, Nitrogen e. Nitrogen, Oxygen 17) Which of the following observations is evidence of large-scale, catastrophic collisions in our Solar System? a. The very large iron core in Mercury b. The rings of Saturn c. The Tharsis volcanoes on Mars d. The 2009 Yankees World Series victory e. The Himalaya mountains in Asia 18) Why is the greenhouse effect on Mars so much weaker than that on Venus even though both planets have atmospheres made up of 95% carbon dioxide? a. Venus thick clouds absorb more infrared radiation from the Sun b. The liquid water that was once on Mars absorbed all the carbon dioxide c. Venus has sulfuric acid rain which causes its atmosphere to heat up more d. Mars atmosphere is much less dense than Venus atmosphere e. Venus atmosphere contains additional greenhouse gases like water vapor 19) It is likely that there are several Earth masses of rocky material in Jupiter. Where is it probably located? a. In the core of the planet b. Mixed in with atmospheric gases c. In solid particles floating in liquid metallic hydrogen d. In atmospheric dust clouds e. In the Red Spot
20) The order of the planets in increasing mean distance from the Sun is: a. Mercury, Venus, Mars, Earth, Saturn, Jupiter, Uranus, Neptune b. Mercury, Mars, Venus, Earth, Jupiter, Uranus, Neptune c. Mars, Venus, Earth, Mercury, Jupiter, Saturn, Uranus, Neptune d. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune e. Mercury, Venus, Mars, Earth, Jupiter, Saturn, Neptune 21) Which of the following statements is a good description of the appearance of Neptune? a. Deep blue color with a few prominent cloud features b. Many conspicuous zones and belts in its cloud layer c. Nearly featureless greenish ball d. Distinctly non-spherical in shape e. Yellow-orange with red spots 22) The tidal force on the Earth (from Sun and Moon) is strongest as a. New moon b. First quarter c. Third quarter d. Blue moon e. No specific phase 23) If the temperature of an ideal thermal radiator is doubled a. Its wavelength of peak emission will get bluer b. Its wavelength of peak emission will get redder c. Its wavelength of peak emission will not change d. Its spectrum will develop two peaks e. Its spectrum will not change 24) If the Earth were moved to twice its current distance from the Sun, the force of gravity from the Sun would be a. Increased by a factor of 4 b. Increased by a factor of 2 c. Unchanged d. Decreased by a factor of 4 e. Decreased by a factor of 2
25) Which of the following is the best indicator of a relatively young planet surface? a. A low average density b. Numerous volcanic cones c. Faults indicative of tectonic spreading d. Saturated cratering e. Smooth maria 26) Which rocky planet has the densest atmosphere? a. Mercury b. Venus c. Earth d. The Moon e. Mars 27) Which rocky planet has the highest mountain or volcano? a. Mercury b. Venus c. Earth d. The Moon e. Mars 28) The clouds of Jupiter consist of ices of a. SO 2 & O 2 b. CO 2 & N 2 c. CO 2 & H 2 O d. NH 3 & O 2 e. NH 3 & H 2 O 29) The clouds of Neptune consist mostly of a. SO 2 b. CO 2 c. CH 4 d. NH 3 e. H 2 O
30) The albedo of a planet is a. The fraction of incident sunlight absorbed b. The fraction of incident sunlight directly reflected c. The tilt of the planet s rotation axis d. The fraction of incident sunlight absorbed in the atmosphere alone e. The ratio of the rotation period to the orbital period 31) Which atom or molecule is much more common in Venus atmosphere than in either of Earth s or Mars? a. N 2 b. O 2 c. H 2 0 d. SO 2 e. Ar