Simon P. Balm

Astronomy 2

Midterm #2 Sample Questions


1. Mercury can be characterized as having

A. a Moon-like surface and an Earth-like interior.

B. both surface and interior like that of the Moon.

C. an Earth-like surface and a Moon-like surface.

D. a surface and interior significantly different from either the Moon or Earth.


2.Venus appears to be very bright in our skies at certain times because

A. even though its surface is very dark, it is relatively close to the Sun.

B. it is glowing from the heat of its surface, where the temperature is 750 K.

C. its rocky surface is shiny, like the surface of new volcanic lava.

D. it is relatively close to the Sun, Earth is close to it, and it is covered by very reflective clouds.


3. In the mapping of Venus by the orbiting Magellan spacecraft, what parameter was measured by the sensors to produce three-dimensional maps of the planet's surface?

A. time delay of the return of reflected radio waves

B. pairs of photographs, taken from different angles, that were then combined stereoscopically to produce contour maps

C. precise photographs of the extreme limb of the planet, taken at UV wavelengths to which the atmosphere is transparent, which showed detailed profiles of the planet's surface

D. wavelength and hence the Doppler shift of reflected radio waves


4. The gas that is the major constituent of the atmospheres of Venus and Mars and a minor constituent of Earth's atmosphere is

A. H2O.

B. N2.

C. CO2.

D. O2.


5. Which of the following is not true concerning the view from a Moon base that can be seen from Earth?

A. The Earth is always in view at approximately the same position in the sky.

B. The Sun is not always in the sky.

C. The Earth shows all the phases of crescent, quarter, gibbous, and full in a period of one month.

D. The Earth rises, sets, and moves across the lunar sky.


6. On Mars, where are most of the extinct volcanoes located?

A. in the northern hemisphere

B. around the southern polar cap

C. along the bottom of the deep valley, Valles Marineris, which was originally formed by enormous geological stresses

D. in a line along the equator, the line of maximum tidal stress on the planet


7. Our planetary system consists of

A. one large planet, and many small planets of about the same size, all accompanied by small moons.

B. large and small planets, all of them accompanied by small moons, none of which are as large as a planet.

C. large and small planets, some accompanied by moons as large as the smaller planets.

D. a series of planets of about the same size, some of which are accompanied by moons, the largest of which are as big as the planets themselves.


8. A major feature of the atmosphere of Mars is

A. occasional strong winds and dust storms.

B. very dense clouds shrouding most of the planet.

C. a chemical mixture very similar to that of Earth.

D. very high temperatures and pressures.


9. Mars experiences similar seasonal changes to those on Earth because

A. it has about the same shape of elliptical orbit as that of the Earth, producing similar changes in solar radiation intensity as the planet orbits the Sun.

B. its spin axis is tilted at about the same angle to its orbital plane as is the Earth's axis.

C. the length of its day is very close to an Earth day.

D. the length of its year is very close to that of Earth.


10. What is the major constituent of the atmosphere of the Earth?

A. CO2

B. N2

C. H2

D. H2O


11. Water exists on Mars. Where and in what state does it NOT exist on this planet?

A. as liquid, flowing in river valleys

B. in permafrost, below the surface

C. in polar icecaps

D. as water vapor in the atmosphere and as clouds


12. Which particular chemical associated with volcanic emissions has been detected by various techniques in amounts that appear to vary significantly over short time scales, indicating the presence of active volcanoes on Venus at the present time?

A. carbon in CO2

B. ammonia and methane gases

C. silicon and silicate dusts

D. sulfur and sulfur compounds


13. The mass of an extrasolar planet is high and its atmosphere is relatively cool. What are the chances for the retention of gases within its atmosphere?

A. good for light (H2 and He) molecules but poor for heavier (CH4, NH3, H2O) molecules

B. good for all gases, including light (H2 and He) and heavier (CH4, NH3, H2O) molecules

C. poor for all gases because of the low temperature, thus all gases will be leaving Jupiter continuously

D. good for heavier (CH4, NH3, H2O) molecules but poor for light (H2 and He) molecules



If one were on the planet Venus viewing the Sun through the clouds, where would the Sun appear to rise as Venus rotated?

A. the east

B. the north, because the spin axis of Venus is parallel to the plane of its orbit.

C. The Sun would not rise or set because Venus rotates synchronously, keeping one side always toward the Sun.

D. the west


15. The period and direction of rotation of Mars are

A. about twice as long as Earth's period, about 48 hours, in the same direction as Earth.

B. a little longer than 1 Earth day, in the opposite direction to Earth.

C. about 240 days, in the opposite direction to Earth.

D. a little longer than 24 hours, in the same direction as the Earth.


16. The lunar maria appear smooth because they are

A. ancient sea beds, now dry, dating back to when the Moon had a denser atmosphere and rainfall was abundant.

B. recent lava flows, occurring within the last billion years, which have obliterated earlier craters.

C. regions where craters have been obliterated by crustal deformation caused by hot spots and volcanic lava flow from the underlying molten mantle.

D. ancient lava flows that occurred soon after the end of an early period of intense bombardment and have had relatively few impacts since then.


17. The severe atmospheric conditions that quickly destroyed spacecraft, which were soft-landed on the surface of Venus, were

A. high temperatures, high pressures, and corrosive acid clouds and mist.

B. high temperatures, low atmospheric pressure, and intense UV radiation from the Sun.

C. very low temperatures, a near vacuum, and corrosive alkaline clouds and mist.

D. intense sunlight, including UV, very high pressures, and very low temperatures.


18. Why is the surface of Venus hotter than that of Mercury, even though Mercury is much closer to the Sun?

A. Chemical reactions within the thick clouds and dense atmosphere are continuously supplying heat to the surface.

B. Continuous volcanic activity releases large quantities of hot lava onto the surface.

C. Venus rotates rapidly, thereby ensuring that its entire surface is being heated regularly and uniformly.

D. The thick CO2 atmosphere prevents re-emission into space of the heat absorbed from sunlight.


19. What is considered to be the most likely source for the deposits of ice that have been discovered at the lunar poles?

A. the Moon's original shallow oceans

B. comets that have crashed onto the lunar surface

C. evaporation of subsurface water from lower latitudes on the Moon, which are heated by the Sun, and subsequent condensation at the poles

D. molten lava, which releases water as it cools


20. If you are on Mercury and the time is noon (Sun directly overhead), what time of day will it be one Mercurian year later (after Mercury has orbited the Sun once)?

A. noon

B. It could be any time, because Mercury rotates independently of its revolution.

C. midnight

D. just after sunset


21. Tectonic activity on Venus differs from that on Earth in that

A. active crustal deformation appears to be completely absent.

B. the lithosphere appears to be softer or more plastic and cannot support the creation and motion of solid plates.

C. the lithosphere appears to be cooler and thicker and is therefore too rigid to break up into moving plates.

D. mantle convection appears to be more vigorous and has broken the lithosphere into a multitude of small plates instead of a few large ones.


22. The Moon has

A. an atmosphere of CO2, but no evidence of water.

B. a lot of evidence for an atmosphere and the presence of liquid water (e.g., wind erosion and winding river valleys).

C. no measurable atmosphere or liquid water.

D. no measurable atmosphere, but plenty of groundwater.


23. Based on its mean density of 2000 kg/m3, Pluto is most likely made of

A. rock and iron

B. rock and ice

C. gas and ice

D. only ice


24. What protects us from the damaging radiation effects of the high-speed solar wind that flows through interplanetary space?

A. the rapid rotation of the Earth, which deflects most of the solar wind

B. the Moon, whose gravitational field shields us from the solar wind

C. Earth's atmosphere

D. the Earth's magnetic field


25. Which of the following types of space mission is best for making direct sampling measurements of a planet?

A. flyby

B. orbiter

C. lander

D. none of these involve direct sampling


26. Which planet most resembles the Moon in visible surface features and atmosphere?

A. Venus

B. Mercury

C. Mars

D. Earth


27. What caused the formation of mountain ranges on Earth like the Rocky Mountains and the Andes?

A. collisions of two tectonic plates, where one is folded into mountains while the other is thrust underneath

B. two tectonic plates being pushed apart by molten rock that is being forced up between them

C. heat from Earth's interior causing Earth's crust to expand and then crumple

D. the carving of continents by ice sheets during ice ages, with the mountains left behind as "islands" in a sea of glaciers



The correct sequence of planets in our solar system from the Sun outward is

A. Mercury, Venus, Earth, Mars, Saturn, Uranus, Jupiter, Neptune, Pluto.

B. Mercury, Earth, Venus, Mars, Jupiter, Saturn, Uranus, Pluto, Neptune.

C. Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus, Pluto, Neptune.

D. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.


29. Determination of the chemical composition of the atmospheres of the planets is carried out most effectively by what type of study?

A. Doppler radar

B. measurement of their relative mean densities

C. measurement of their atmospheric temperature

D. spectroscopy—the measurement of absorption features in their spectra



30. To form the present structure of Earth, which of the following mechanisms is most likely to have taken place while Earth was molten?

A. Heavy elements sank to the center under gravity, while lighter materials rose to the surface and solidified into rocks.

B. Lighter elements sank to the center leaving the heavier material to form the rocky surface after cooling.

C. Hydrogen and helium became highly compressed by gravity and sank to the core below a layer of heavier rocky material.

D. All materials were thoroughly mixed by convection in the molten state, and Earth remained mixed as it cooled.


31. If the phase of the Moon as seen from the Earth is full, what would be the phase of the Earth as seen from the Moon?

A. full

B. new

C. 1st quarter

D. waxing gibbous


32. The albedo of a planet is the fraction of energy that is

A. reradiated into space as infrared radiation by the planet.

B. reflected by the whole planet, including atmosphere and surface.

C. absorbed.

D. reflected by clouds in the atmosphere.


33. An interstellar cloud can become unstable and form a planetary system if

A. gravity > pressure  

B. gravity = pressure  

C. gravity = 0  

D. pressure > gravity


34. Which of the following planets does not have a moon?

A. Uranus  

B. Jupiter  

C. Mercury  

D. Mars


35. Marble is

A. a metamorphic rock

B. an igneous rock

C. a rock that fell to Earth from space (a meteorite)

D. a sedimentary rock


36. The age of Earth is considered to be

A. about 65 million years.

B. about 4.5 billion years.

C. about 4.5 million years.

D. 13.7 billion years.


37. Which of the following molecular species plays a major role in the greenhouse effect in planetary atmospheres?

A. ozone

B. nitrogen

C. carbon dioxide

D. oxygen


38. The waves that geologists and geophysicists use to probe the inside of Earth are

A. seismic waves.

B. sound waves.

C. radar waves.

D. microwaves.


39. All the boundaries of the major moving tectonic plates on Earth's surface coincide with

A. the edges of the continental shelves around the major continents.

B. regions where ocean depths are greatest.

C. the occurrence of major auroral activity.

D. the positions of maximum earthquake occurrence.


40.   The Van Allen belts are

A. regions of the Earth in which no seismic activity is detected from earthquakes.

B. dense collections of small rocks surrounding the major planets.

C. two doughnut-shaped rings of charged particles, surrounding the equatorial regions of Earth at very high altitudes.

D. undersea mountain ranges in the centers of the oceans.


41. The terminator on the Moon is a line

A. joining north and south lunar poles, passing through the center of the largest mare, Imbrium, representing 0° of lunar longitude.

B. between the near and far sides of the Moon.

C. between the solar-illuminated and dark hemispheres.

D. along the equator, between northern and southern hemispheres.


42. To observers on Earth, the Moon shows

A. only its northern half because of the tilt of the Moon's rotational axis.

B. its whole surface once per month as it rotates.

C. only one side to Earth at all times.

D. its whole surface once per year as Earth moves around the Sun.


43. The Moon has

A. an atmosphere of CO2, but no evidence of water.

B. a lot of evidence for an atmosphere and the presence of liquid water (e.g., wind erosion and winding river valleys).

C. no measurable atmosphere or liquid water.

D. no measurable atmosphere, but plenty of groundwater.


44. The inner planets, in order of increasing planetary radius, are

A. Mercury, Venus, Earth, Mars.

B. Mercury, Mars, Venus, Earth.

C  Mercury, Venus, Earth, Mars.

D. Mercury, Earth, Venus, Mars.


45. In one orbit around the Sun, Mercury rotates around its axis

A. twice.

B. 3 times.

C. 1˝ times.

D. once, in a synchronous orbit.


46. On how many occasions has a spacecraft had the opportunity to photograph the planet Mercury?

A. five times

B. once

C. three times

D. twice


47. When Venus is seen at new phase i.e. when we see none of the illuminated hemisphere, a ring of light is seen around it. What does this tell us about Venus?

A. Venus has auroral displays similar to those on Earth which extend over the whole planet.

B. Venus has a thick atmosphere that refracts sunlight toward us.

C. The surface of Venus is so hot that it glows, even on its dark side.

D. That its atmosphere is much more reflective than the Earth's


48. The length of one solar day on Venus (i.e., time between successive sunrises) is

A. 243 Earth days.

B. 224 Earth days.

C. 88 Earth days.

D. 117 Earth days.


49. A ground-based visual telescopic view of Venus reveals

A. a completely cloud-shrouded planet with high atmospheric wind speeds.

B. a dark smooth surface with few mountain ranges.

C. evidence of ice-covered polar caps and huge dust storms.

D. a crater-covered surface of reddish color.


50. The polar caps on Mars are most likely made up of

A. water and CO2 ices.

B. light-colored dust blown there by intense dust storms and large dust devils.

C. volcanic outflow of light-colored lava and dust similar to that produced by Earth-based volcanoes.

D. sulfur dioxide and sulfur compounds.