Astronomy 104 Homework 7
12.In the absence of a greenhouse effect, what would happen to Earth's oceans? a.They would evaporate. b.They would freeze over. c.They would be rapidly absorbed into the surface rocks. d.They would dissociate into ozone and hydrogen.
b
14.Venus and Earth probably formed with similar amounts of carbon dioxide in their secondary atmospheres. Which of the following is true? a.The majority of Earth's carbon dioxide escaped into space because of its hotter temperature, whereas Venus's carbon dioxide remains gravitationally bound to Venus. b.The majority of Earth's carbon is now bound up in rock, whereas Venus's remains in its atmosphere. c.Earth lost more of its secondary atmosphere because it was bombarded by more planetesimals than Venus. d.The majority of Earth's carbon was absorbed by plants during photosynthesis.
b
16.If photosynthesis were to disappear on Earth, a.the atmosphere would become less dense. b.oxygen would disappear from the atmosphere. c.the atmosphere would become hotter. d.nitrogen would disappear from the atmosphere.
b
19.Why are Jupiter and Saturn not perfectly spherical? a.They formed from the collision of two large planetesimals. b.They rotate rapidly. c.They have storms that develop preferentially along their equators. d.They have very active auroras that heat the atmospheres along the poles.
b
20.If you could find a large enough ocean, which one of these planets would float in it? a.Uranus b.Saturn c.Neptune d.Mars
b
11.The main greenhouse gases in the atmosphere of the terrestrial planets are a.oxygen and nitrogen. b.methane and ozone.c.carbon dioxide and water vapor. d.hydrogen and helium.
c
18.Jupiter is approximately _______ times more massive than Earth. a.10 b.50 c.300 d.1,000
c
21.When you look at the visible surface of a gas giant planet, you are looking at that planet's a.oceans. b.core. c.atmosphere. d.metallic hydrogen
c
5.We have direct evidence for the current existence of water on the surface of which terrestrial object?a.Mercury b.Venus c.Mars d.Ganymede
c
9.Which of the following processes did notcontribute gas to Earth's secondary atmosphere? a.volcanism b.accretion c.oxidation d.comet impacts
c
13.The greenhouse effect is the a.trapping of infrared radiation by the atmosphere. b.accentuated growth of plants near the equator, compared to other regions. c.capturing of visible and UV radiation from the Sun the atmosphere. d.shielding of life-forms from solar UV radiation by the ozone layer.
a
2.Which terrestrial object shows the least evidence of recent volcanic activity? a.Mercury b.Venus c.Earth d.Mars
a
6.Which of the following statements is false? a.The surface of Venus has very few craters primarily because asteroids burn up in its thick atmosphere. b.Geological features and the chemical composition of some rocks on Mars suggest liquid water flowed on the surface in the past, but not at the present time. c.Darker regions of the Moon's surface have fewer craters and are approximately 1 billion years younger than the lighter regions. d.Volcanoes on Mars are larger, on average, than Earth's volcanoes because Mars does not have moving continental plates.
a
8.Why did the terrestrial planets lose the majority of the gas in their primary atmospheres? a.They were too hot and their escape velocities too low to hold onto them. b.The solar wind was too strong and blew these gases off the planets. c.Their high surface temperatures made the gas chemically react with the rock. d.The initial gases were so heavy when the planet differentiated that they sank to the core.
a
1.Earth's innermost core is solid, not liquid, because a. the core temperature is too low to melt iron. b.differentiation caused all of the heavy, solid material to sink to the bottom while Earth was forming. c.all the liquid has moved up into the mantle via convection. d.the pressure is too high for the material to be in a liquid state.
d
10.If the carbon dioxide in Earth's rocks were suddenly released into its atmosphere, what would happen? a.It would rapidly escape into space. b.It would dissociate into carbon and oxygen. c.It would collect as ice on the north and south poles. d.It would cause a runaway greenhouse effect.
d
15._________ in our atmosphere is a direct consequence of the emergence of life. a.Carbon dioxide b.Water vapor c.Nitrogen d.Oxygen
d
17.The giant planets are made primarily of a.water and carbon dioxide. b.oxygen and nitrogen. c.methane. d.molecular hydrogen and helium
d
3.The largest volcanic mountains in the Solar System are found on a.Mercury. b.Venus. c.Earth. d.Mars.
d
4.Which is not a reason that we suspect Mars once had liquid water on its surface? a.Mapping satellites have detected dry riverbeds. b.Rovers have detected minerals that must have formed in the presence of liquid water. c.Mapping satellites have detected outflow channels coming from impact craters. d.The observed presence of water ice in Mars's polar icecaps.
d
7.What is the reason Mercury has so little gas in its atmosphere? a.Its mass is small. b.It has a high temperature. c.It is close to the Sun. d.Its escape velocity is low. e.all of the above
e