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ASTR 1020 FINAL EXAM LATEST EXAM
| ALL QUESTIONS AND CORRECT
ANSWERS | GRADED A+ | VERIFIED
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The main process by which heat flows upward through the lithosphere is A) conduction. B) convection. C) radiation. D) accretion. E) differentiation. ------CORRECT ANSWER---------------A) conduction. Heat escapes from a planet's surface into space by thermal radiation. Planets radiate almost entirely in the wavelength range of the A) infrared. B) radio. C) visible. D) ultraviolet. E) none of the above ------CORRECT ANSWER---------------A) infrared. Which of the following worlds have the thinnest lithospheres? A) Earth and the Moon B) Venus and the Moon C) Mercury and Venus D) Earth and Mars E) Earth and Venus ------CORRECT ANSWER---------------E) Earth and Venus Which of the following best describes why the smaller terrestrial worlds have cooler interiors than the larger ones?
A) They were cooler when they formed. B) The smaller ones are farther from the Sun. C) They have relatively fewer radioactive elements. D) They have relatively more surface area compared to their volumes. E) They had more volcanic eruptions in the past, which released their internal heat. ------CORRECT ANSWER---------------D) They have relatively more surface area compared to their volumes. Which of the terrestrial worlds has the strongest magnetic field? A) Mars B) Earth C) the Moon D) Venus E) Mercury ------CORRECT ANSWER---------------B) Earth Why does Earth have the strongest magnetic field among the terrestrial worlds? A) It is the only one that has a metallic core. B) It rotates much faster than any other terrestrial world. C) It is the only one that has both a partially molten metallic core and reasonably rapid rotation. D) It is by far the largest terrestrial world. E) It is the most volcanically active world. ------CORRECT ANSWER---------- -----C) It is the only one that has both a partially molten metallic core and reasonably rapid rotation. Which of the following most likely explains why Venus does not have a strong magnetic field? A) It does not have a metallic core. B) Its rotation is too slow. C) It is too close to the Sun. D) It is too large. E) It has too thick an atmosphere. ------CORRECT ANSWER---------------B) Its rotation is too slow.
How large is an impact crater compared to the size of the impactor? A) the same size B) 10-20 percent larger C) 10 times larger D) 100 times larger E) 1,000 times larger ------CORRECT ANSWER---------------C) 10 times larger The relatively few craters that we see within the lunar maria A) were formed by impacts that occurred before those that formed most of the craters in the lunar highlands. B) were formed by impacts that occurred after those that formed most of the craters in the lunar highlands. C) were created by the same large impactor that led to the formation of the maria. D) are volcanic in origin, rather than from impacts. E) are sinkholes that formed when sections of the maria collapsed. ------ CORRECT ANSWER---------------B) were formed by impacts that occurred after those that formed most of the craters in the lunar highlands. When we see a region of a planet that is not as heavily cratered as other regions, we conclude that A) there is little volcanic activity to create craters. B) the planet is rotating very slowly and only one side was hit by impactors. C) the planet formed after the age of bombardment and missed out on getting hit by leftover planetesimals. D) the surface in the region is older than the surface in more heavily cratered regions. E) the surface in the region is younger than the surface in more heavily cratered regions. ------CORRECT ANSWER---------------E) the surface in the region is younger than the surface in more heavily cratered regions.
Volcanism is more likely on a planet that A) is closer to the Sun. B) is struck often by meteors and solar system debris. C) has high internal temperatures. D) doesn't have an atmosphere or oceans. ------CORRECT ANSWER-------- -------C) has high internal temperatures. Shallow-sloped shield volcanoes are made from lava that A) is as runny as liquid water. B) has a medium viscosity. C) has a high viscosity. D) can have any viscosity. ------CORRECT ANSWER---------------B) has a medium viscosity. Steep-sided stratovolcanoes are made from lava that A) is as runny as liquid water. B) has a medium viscosity. C) has a high viscosity. D) can have any viscosity. ------CORRECT ANSWER---------------C) has a high viscosity. What type of stresses broke Earth's lithosphere into plates? A) impacts of asteroids and planetesimals B) internal temperature changes that caused the crust to expand and stretch C) the circulation of convection cells in the mantle, which dragged against the lithosphere D) cooling and contracting of the planet's interior, which caused the mantle and lithosphere to be compressed E) volcanism, which produced heavy volcanoes that bent and cracked the lithosphere ------CORRECT ANSWER---------------C) the circulation of convection cells in the mantle, which dragged against the lithosphere
B) the eruption of molten rock from a planet's interior to its surface C) the disruption of a planet's surface by internal stresses D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather ------CORRECT ANSWER- --------------A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface A planet is most likely to have tectonic activity if it has A) low surface gravity. B) high surface gravity. C) low internal temperature. D) high internal temperature. E) a dense atmosphere. ------CORRECT ANSWER---------------D) high internal temperature. What kind of surface features may result from tectonics? A) mountains B) valleys C) volcanos D) cliffs E) all of the above ------CORRECT ANSWER---------------E) all of the above What is basalt? A) any substance that evaporates easily and is a gas, liquid, or ice on Earth B) a type of rock that makes relatively low-viscosity lava C) a type of metal that tends to create stratovolcanoes when eruptions occur D) a type of mineral that is the main ingredient of sea salt E) another name for lava ------CORRECT ANSWER---------------B) a type of rock that makes relatively low-viscosity lava How did the lunar maria form?
A) Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins. B) The early bombardment created heat that melted the lunar surface in the regions of the maria. C) Volatiles escaping from the Moon's interior heated and eroded the surface in the regions of the maria. D) The giant impact that created the Moon left smooth areas that we call the maria. E) The maria are the result of gradual erosion by micrometeorites striking the Moon. ------CORRECT ANSWER---------------A) Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins. Why does the Moon have a layer of powdery "soil" on its surface? A) Large impacts shattered lunar rock to make this soil. B) The soil exists because the Moon accreted from powdery material after a giant impact blasted Earth. C) Volatiles escaping from the Moon's interior bubble upward and make the soil. D) The soil is the result of the same processes that make powdery sand on Earth. E) It's the result of gradual erosion by micrometeorites striking the Moon. --- ---CORRECT ANSWER---------------E) It's the result of gradual erosion by micrometeorites striking the Moon. The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that A) erosion destroyed the smaller craters that formed on the basin. B) Mercury's atmosphere prevented smaller objects from hitting the surface. C) only very large impactors hit Mercury's surface in the past. D) the Caloris Basin formed toward the end of the solar system's period of heavy bombardment. E) the Caloris Basin was formed by a volcano. ------CORRECT ANSWER--- ------------D) the Caloris Basin formed toward the end of the solar system's period of heavy
C) the presence of vast canals discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell D) rocks of many different types jumbled together, as would occur if there had once been a great flood in the region, found by the Mars Pathfinder E) some very old craters that appear to have been eroded by rain ------ CORRECT ANSWER---------------C) the presence of vast canals discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell The polar caps on Mars are composed of A) pure solid carbon dioxide. B) pure water ice. C) mostly solid carbon dioxide and some water ice. D) mostly water ice and some solid carbon dioxide. E) There are no polar caps on Mars. ------CORRECT ANSWER--------------- C) mostly solid carbon dioxide and some water ice. How have we been able to construct detailed maps of surface features on Venus? A) by studying Venus from Earth with powerful telescopes B) by studying Venus with powerful optical telescopes on spacecraft that were sent to orbit Venus C) by making computer models of geological processes on Venus D) by using radar from spacecraft that were sent to orbit Venus E) by landing spacecraft on the surface for close-up study ------CORRECT ANSWER---------------D) by using radar from spacecraft that were sent to orbit Venus Which two geological processes appear to have been most important in shaping the present surface of Venus? A) impacts and volcanoes B) impacts and tectonics C) tectonics and erosion D) volcanoes and tectonics
E) volcanoes and erosion ------CORRECT ANSWER---------------D) volcanoes and tectonics Which of the following show evidence of ancient river beds? A) the Moon B) Mercury C) Venus D) Mars E) all of the above ------CORRECT ANSWER---------------D) Mars What percentage of the mass of the solar nebula consisted of elements other than hydrogen and helium? A) 0 percent B) 0.1 percent C) 2 percent D) 20 percent E) 80 percent ------CORRECT ANSWER---------------C) 2 percent Where did the elements heavier than hydrogen and helium come from? A) They were produced in the Big Bang. B) They evolved from hydrogen and helium shortly after the Big Bang. C) They were produced inside stars. D) They were produced inside dense interstellar gas. E) all of the above ------CORRECT ANSWER---------------C) They were produced inside stars. Why did the solar nebula heat up as it collapsed? A) Nuclear fusion occurring in the core of the protosun produced energy that heated the nebula. B) As the cloud shrank, its gravitational potential energy was converted to kinetic energy and then into thermal energy.
B) Any planets that once orbited in the opposite direction or a different plane were ejected from the solar system. C) The laws of conservation of energy and conservation of angular momentum ensure that any rotating, collapsing cloud will end up as a spinning disk. D) The Sun formed first, and as it grew in size it spread into a disk, rather like the way a ball of dough can be flattened into a pizza by spinning it. E) Luck explains it, as we would expect that most other solar systems would not have all their planets orbiting in such a pattern. ------CORRECT ANSWER---------------C) The laws of conservation of energy and conservation of angular momentum ensure that any rotating, collapsing cloud will end up as a spinning disk. Which of the following lists the ingredients of the solar nebula from highest to lowest percentage of mass of the nebula? A) light gases (H, He), hydrogen compounds (H2O, CH4, NH3), rocks, metals B) hydrogen compounds (H2O, CH4, NH3), light gases (H, He), rocks, metals C) light gases (H, He), hydrogen compounds (H2O, CH4, NH3), metals, rocks D) hydrogen compounds (H2O, CH4, NH3), light gases (H, He), metals, rocks E) hydrogen compounds (H2O, CH4, NH3), rocks, metals, light gases (H, He) ------CORRECT ANSWER---------------A) light gases (H, He), hydrogen compounds (H2O, CH4, NH3), rocks, metals What percentage of the solar nebula's mass consisted of hydrogen and helium gases? A) 0.5 percent B) 5 percent C) 50 percent D) 98 percent E) 100 percent ------CORRECT ANSWER---------------D) 98 percent
What percentage of the solar nebula's mass consisted of rocky material? A) 0 percent B) 0.4 percent C) 2 percent D) 20 percent E) 80 percent ------CORRECT ANSWER---------------B) 0.4 percent What kind of material in the solar nebula could remain solid at temperatures as high as 1,500 K, such as existed in the inner regions of the nebula? A) rocks B) metals C) silicon-based minerals D) hydrogen compounds E) molecules such as methane and ammonia ------CORRECT ANSWER---- -----------B) metals What was the frost line of the solar system? A) the distance from the Sun where temperatures were low enough for metals to condense, between the Sun and the present-day orbit of Mercury B) the distance from the Sun where temperatures were low enough for rocks to condense, between the present-day orbits of Mercury and Venus C) the distance from the Sun where temperatures were low enough for hydrogen compounds to condense into ices, between the present-day orbits of Mars and Jupiter D) the distance from the Sun where temperatures were low enough for asteroids to form, between the present-day orbits of Venus and Earth E) the distance from the Sun where temperatures were low enough for hydrogen and helium to condense, between the present-day orbits of Jupiter and Saturn ------CORRECT ANSWER---------------the distance from the Sun where temperatures were low enough for hydrogen compounds to condense into ices, between the present-day orbits of Mars and Jupiter
C) By the time planetesimals grew to a large enough mass to hold onto an atmosphere, the solar nebula had been blown away. D) Any planet forming beyond Neptune's orbit would have been scattered outside of the solar system by gravitational encounters. E) There may be, but they would be so faint that astronomers have not found them yet. ------CORRECT ANSWER---------------C) By the time planetesimals grew to a large enough mass to hold onto an atmosphere, the solar nebula had been blown away. Observations of young stars (as well as theory) tell us that when the Sun was young the solar wind A) was weaker than it is today. B) was stronger than it is today. C) was about the same strength as it is today. D) was nonexistent. E) blew outward only along the Sun's poles. ------CORRECT ANSWER------ ---------B) was stronger than it is today. Which of the following has not been detected around other stars in the Galaxy? A) a collapsing nebula of gas B) flattened, spinning disks C) jovian planets D) terrestrial planets E) strong stellar winds ------CORRECT ANSWER---------------D) terrestrial planets At first, the Sun's present-day rotation seems to contradict the prediction of the nebular theory because A) the theory predicts that the axis of rotation should not be perpendicular to the orbital plane of the planets, but it is. B) the axis of rotation precesses slowly, which the theory does not predict. C) the present-day rotation is in the opposite direction from that predicted by the theory.
D) the theory predicts that the Sun should have been rotating fast when it formed, but the actual rotation is fairly slow. E) the theory predicts that the Sun should not have been rotating when it formed, but the Sun actually rotates today. ------CORRECT ANSWER-------- -------D) the theory predicts that the Sun should have been rotating fast when it formed, but the actual rotation is fairly slow. According to our theory of solar system formation, why does the Sun rotate slowly today? A) The Sun once rotated much faster, but it transferred angular momentum to charged particles caught in its magnetic field and then blew the particles away with its strong solar wind. B) The Sun once rotated much faster, but it transferred angular momentum to planets and other objects during close encounters. C) The Sun once rotated much faster, but it lost angular momentum due to internal friction. D) The Sun once rotated much faster, but it lost angular momentum because everything slows down with time. E) The Sun was born rotating slowly because the solar nebula had very little angular momentum. ------CORRECT ANSWER---------------A) The Sun once rotated much faster, but it transferred angular momentum to charged particles caught in its magnetic field and then blew the particles away with its strong solar wind. Which of the following are relatively unchanged fragments from the early period of planet building in the solar system? A) the moons of Mars B) asteroids C) Kuiper belt comets D) Oort cloud comets E) all of the above ------CORRECT ANSWER---------------E) all of the above According to the nebular theory, what are asteroids and comets? A) They are the shattered remains of collisions between planets.
Based on our current theory of Earth's formation, the water we drink comes from A) ice that condensed in the solar nebula in the region where Earth formed. B) chemical reactions that occurred in Earth's crust after Earth formed. C) chemical reactions that occurred in Earth's core after Earth formed. D) material left behind during the giant impact that formed the Moon. E) comets that impacted Earth. ------CORRECT ANSWER---------------E) comets that impacted Earth. The heavy bombardment phase of the solar system lasted A) several million years. B) several tens of millions of years. C) several hundreds of millions of years. D) about a billion years. E) to the present time. ------CORRECT ANSWER---------------C) several hundreds of millions of years. Which of the following is not evidence supporting the giant impact theory for the formation of the Moon? A) Computer simulations show that the Moon could really have formed in this way. B) The composition of the Moon is similar to that of Earth's outer layers. C) The Moon is depleted of easily vaporized materials, as we would expect from the heat of an impact. D) Scientists have found several meteorites that appear to be the remains of the object that caused the giant impact. E) We see signatures of giant impacts on other planets. ------CORRECT ANSWER---------------D) Scientists have found several meteorites that appear to be the remains of the object that caused the giant impact. Which of the following puzzles in the solar system cannot be explained by a giant impact event? A) the formation of the Moon
B) the large metallic core of Mercury C) the backward rotation of Venus D) the extreme axis tilt of Uranus E) the orbit of Triton in the opposite direction to Neptune's rotation ------ CORRECT ANSWER---------------E) the orbit of Triton in the opposite direction to Neptune's rotation The nebular theory of the formation of the solar system successfully predicts all but one of the following. Which one does the theory not predict? A) Planets orbit around the Sun in nearly circular orbits in a flattened disk. B) the compositional differences between the terrestrial and jovian planets C) the equal number of terrestrial and jovian planets D) asteroids, Kuiper-belt comets, and the Oort cloud E) the craters on the Moon ------CORRECT ANSWER---------------C) the equal number of terrestrial and jovian planets The age of our solar system is approximately A) 10,000 years. B) 3.8 million years. C) 4.6 million years. D) 4.6 billion years. E) 14 billion years. ------CORRECT ANSWER---------------D) 4.6 billion years. The age of the solar system can be established by radioactive dating of A) the oldest Earth rocks. B) the oldest rocks on the Moon. C) the oldest meteorites. D) the atmosphere of Mars. E) It hasn't been done yet, but the age of the solar system could be obtained from a sample of Io's surface. ------CORRECT ANSWER------------- --C) the oldest meteorites.
