Name: Period: Date: Astronomy Ch. 10 Mars Review MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Why was the summer of 2003 a fine time for Mars observers? A) The skies were unusually clear and calm. B) Mars' north pole was tilted to face the Earth head-on. C) Mars was closer to us than it has been in over 50,000 years. D) The Mars Rovers returned live images from the surface. E) Mars was even brighter than Venus for several weeks. 1) 2) Mars is best viewed from Earth when it is at A) perihelion. B) conjunction. C) aphelion. D) opposition. E) none of the above 2) 3) What makes the view of Mars in the summer of 2003 so spectacular? A) The feature known as Olympus Mons erupted spewing ash into the Martian atmosphere. B) There were huge dust storms that made the planet appear much brighter than usual. C) Mars had an angular size comparable to the full moon. D) Earth's atmosphere was amazingly clear everywhere for months making the view of spectacular Mars available to everyone. E) Mars was both at perihelion and opposition, creating the perfect viewing conditions from Earth. 3) 4) Why does Mars appear fainter than Venus, as seen from Earth? A) because it is often eclipsed by Jupiter B) because of its red color C) because its two moons block the light from getting to Earth D) because it doesn't have water on its surface E) because it is smaller, farther away and less reflective 4) 5) What physical feature of Mars are atypical compared with the other terrestrial planets? A) its surface composition B) its rotation rate C) its size D) its density E) its atmospheric content 5) 1
6) Which is the correct size order, from smallest to largest? A) Venus, Mars, Earth B) Mercury, Mars, Venus C) Mercury, the Moon, Mars D) Mercury, Venus, Mars E) The Moon, Earth, Mars 6) 7) How long is a day on Mars? A) 243 Earth days B) 9 hours, 55 minutes C) 24 hours, 36 minutes D) 23 hours, 56 minutes E) about 4.2 Earth days 7) 8) How does the axial tilt of Mars compare with our own? A) Like Jupiter, Mars always keeps its equator pointing at the Sun. B) Like Uranus, it is 98 degrees and flopped over on its side. C) Like Saturn, it's about 27 degrees. D) It is about half our own, 12 degrees. E) It is almost identical to the Earth. 8) 9) Unlike Earth, Mars' seasons are affected (enhanced and diminished) by the distance between Mars and the Sun. This is because A) Mars gets closer to the Sun than the Earth does. B) Mars is tilted more on its axis than Earth is. C) an Earth year is shorter. D) the orbit of Mars is significantly more elliptical. E) Earth is closer to the Sun to begin with. 9) 10) Where do the names for the moons of Mars (Phobos and Deimos) come from? A) the sons of Ares and Aphrodite B) the founders of Rome C) the twins depicted in the constellation Gemini D) the names of the dogs of Orion E) the names of their discoverers 10) 11) Why are Mars' seasons more extreme than those of the earth? A) Mars' orbit is more eccentric than our almost circular one. B) Mars' weather is driven by evaporation from the polar ice in its summer. C) Mars' seas dried up long ago. D) Mars' axial tilt is slightly more than our 23.5 degrees. E) All of these contribute to the huge barometric changes that Mars experiences. 11) 12) The most prominent feature of Mars observable from Earth is A) its bright polar caps. B) its two prominent moons. C) the large volcano Olympus Mons. D) its thick atmosphere. E) the prominent feature, Valles Marineris. 12) 2
13) What causes the changing dark and light features visible on the Martian surface from Earth? A) lava fields, similar to those found on the Moon B) highly cratered and eroded areas that are frequently covered and uncovered by dust C) huge storms like those on Jupiter with winds that often reach speeds of hundreds of kilometers per hour D) the flooding of the network of canals from seasonal polar ice melting E) seasonal growth of vegetation 13) 14) Most of the dark regions on Mars visible from Earth are A) volcanic planes like the lunar maria. B) mountainous regions. C) features like the Valles Marineris. D) lava flows from active volcanoes. E) the seasonal growth of vegetation on the planet. 14) 15) The difference between the Grand Canyon and the Valles Marineris is A) the Valles Marineris has craters in and around it. B) the Grand Canyon was formed by water. C) the Valles Marineris has tectonic features surrounding it. D) the Valles Marineris is much larger than the Grand Canyon. E) all of the above 15) 16) Which of these were observed from Earth, prior to spacecraft missions to Mars? A) seasonal changes in the polar caps B) eruptions of Mount Olympus C) dust storms capable of covering the entire planet D) Both A and C are correct. E) All of the above are correct. 16) 17) The deepest depression found on the surface of Mars is the A) Mare Crisium. B) Valles Marineris rift, C) Caloris basin. D) Hellas Basin of Mars. E) Mariannas Trench. 17) 18) Valles Marineris is the most striking example of a(n) A) shield volcano. B) scarp. C) oceanic trench. D) rift valley. E) impact crater. 18) 19) The most striking valley in the solar system is: A) Valhalla on Callisto. B) the Grand Canyon in Arizona. C) the Discovery Scarp of Mercury. D) Valles Marineris on Mars. E) Gwenivere on Venus. 19) 3
20) The largest shield volcano yet discovered is: A) Prometheus on Io. B) Caloris on Mercury. C) Kilimanjaro on Earth. D) Maxwell Mons on Venus. E) Olympus Mons on Mars. 20) 21) Why is the southern hemisphere of Mars believed to be older than the northern? A) The northern hemisphere leans more away from the Sun in winter. B) The northern hemisphere is higher, due to the Tharsis Bulge. C) The southern hemisphere is darker much like the lunar mare. D) The southern hemisphere is more heavily cratered. E) The south polar cap is much thicker than the north one. 21) 22) Olympus Mons and Maxwell Mons are both A) shield volcanoes. B) large features on the surface of Mars. C) features visible from Earth. D) the two largest known volcanoes in the solar system. E) dormant volcanoes. 22) 23) The NASA missions that landed on Mars in 1976 were the A) Vikings I and II. B) Magellan lander. C) the Galileo probe. D) Voyagers. E) Venera 14. 23) 24) What property of Mars is responsible for producing the great heights of its volcanos? A) Mars has more radioactive material than the Earth. B) Its thick crust can support larger peaks, and lower surface gravity does not pull them down as much as on Earth. C) Its volcanoes are made of sulfur, like Io's. D) Its higher surface gravity allows higher peaks to form. E) Its cold temperatures allows the magma to freeze faster. 24) 25) Which of the following characterizes a shield volcano? A) It erupts only briefly before subsiding forever. B) It is formed by moving tectonic plates. C) It will be smaller than cinder cones like Maxwell Mons on Venus. D) It cannot grow very large, for the plates are constantly moving. E) It sits above a hot spot in the planet's mantle. 25) 26) Which of these is not now on the surface of Mars? A) Sojourner B) Pathfinder C) Spirit D) Mars Global Surveyor E) Viking 1 26) 4
27) The first successful landers on the surface of Mars were: A) Spirit and Opportunity in 2004. B) Vikings 1 and 2 in 1976. C) Voyagers 1 and 2 in 1979. D) Mariners 4 and 5 in 1965. E) Pathfinder and Sojourner in 1997. 27) 28) The NASA lander which deployed the first rover, Sojourner, in 1997 was: A) Mars Rover. B) Pathfinder. C) Viking 2. D) South Polar Lander. E) Global Surveyor. 28) 29) The largest difference between Mars' northern and southern hemispheres is that: A) the northern has all the outflows and must have been much hotter. B) the southern is much darker, with large mare-like basaltic lava flows. C) the southern appears older, with more impact craters. D) the southern has a polar cap, but none ever forms in the north. E) the northern is higher overall, despite some high volcanoes in the south. 29) 30) The Tharsis Bulge on Mars is roughly the size of A) New York City B) Texas C) North America D) Mexico E) Asia 30) 31) What is thought to be the reason that there are no small impact craters on Mars? A) Like Venus, Mars' atmosphere is too thick and these meteorites do not survive to make impacts on the surface. B) The wind blows small dust particles, eroding the surface of Mars, erasing small impact craters faster than they can form. C) The surface of Mars is too young to have impact craters. D) Due to the gravitational pull of Mars' moons, most small meteoroids are deflected and never make it to the surface. E) None of the above. Mars has lots of small impact craters. 31) 32) The largest and deepest impact basin found on Mars is: A) Tharsis. B) Caloris. C) Hellas. D) Olympus. E) Meridani. 32) 5
33) That the Tharsis region on Mars has so few craters A) is due to the regions very low elevation. B) is due to annual flooding and water erosion. C) suggests it is at the center of a particularly strong magnetic field. D) proves tectonic activity is taking place. E) suggests it is the youngest region on the planet. 33) 34) The outflow channels on Mars indicate a flood period in the history of Mars. During this time, based on the width and depth of the remaining riverbed, it is thought that the flow rate must have been A) just a small trickle, barely more than a stream of water. B) enormous, as much as 100 times the flow rate of the Amazon River. C) moderate, about the flow rate of the Ohio River. D) significantly large, about the flow rate of the Amazon River. E) fairly large, about the flow rate of the current Colorado River. 34) 35) If water caused the huge outflow channels on Mars, what was the most likely process that formed them? A) large comets that struck Mars B) heat from the impact of the large asteroid that made Hellas C) rainfall from the hydrosphere D) annual melting of the seasonal ice caps E) catastrophic but rare flooding 35) 36) Evidence of liquid water in Mars' distant past suggests that it had a substantial atmosphere compared to what it has presently. What happened to its water vapor? A) Mars initially had such a large Greenhouse effect that the atmosphere became quite hot and slowly escaped. B) It has now all been lost in space, including the carbon dioxide and water vapor. C) The carbon dioxide in its atmosphere dissolved in the water and combined with surface rocks. D) Its atmosphere was mostly hydrogen and helium. Mars' gravity is too weak to hold them. E) The atmosphere has frozen out into the polar ice caps and permafrost as Mars has cooled. 36) 37) Why is Mars red? A) Dust storms on the planet have blasted the planet so fiercely that the rocks have reddened. B) Sulfuric acid rain etched a reddish color into iron-rich surface rocks. C) The ancient volcanoes poured out vast plains of molten sulfur, much as on Io, which has now solidified and preserved the reddish color. D) Mercuric oxide is abundant and has a red tint. E) The iron in the surface rocks have been oxidized over time. 37) 38) One piece of evidence against the possibility of water on Mars is A) the fact that the polar ice caps are made of carbon dioxide ice. B) the current lack of water on Mars. C) the few carbonate rock layers that would have formed on the bottoms of oceans. D) the "hydrated" chemical compounds found on surface rocks all over the planet. E) the volcanic activity on Mars. 38) 6
39) Evidence for a permafrost layer of ice just a few meters below the surface of Mars include A) carbonate rock layers that are in low abundance. B) outflow channels and ancient river deltas. C) river channels and flood plains that look identical to such features on Earth. D) "hydrated" chemical compounds found on surface rocks. E) "fluidized ejecta" craters. 39) 40) Is there evidence of life on Mars? A) Yes, just found as fossils in the sedimentary rocks examined by Spirit. B) Yes, at least at the time the Allen Hills Meteorite was formed, since it has fossils. C) No, nothing suggesting life has ever been discovered. D) Yes, but it is only in the form of microbes found by Viking landers. E) We have confusing and uncertain results to date. 40) 41) The main constituent of the Martian atmosphere is A) helium. B) nitrogen. C) hydrogen. D) carbon dioxide. E) methane. 41) 42) Venus and Mars probably evolved differently from Earth because: A) they have thicker atmospheres than the Earth. B) they formed sooner than Earth. C) they orbit at different distances from the Sun. D) they are slightly bigger than Earth. E) they are more massive than Earth. 42) 43) One of the most unexpected aspects of Mars' atmosphere is A) that it is cloudless. B) that it has such a low density. C) that it is 95% carbon dioxide. D) that it contains water vapor clouds. E) that its troposphere changes altitude. 43) 44) Compare the atmospheres of Mars and Venus. A) Like Earth, nitrogen is the chief atmospheric gas. B) Mars is rich in oxygen, like ours, accounting for its red surface. C) Both are made of hydrogen and helium, like the jovians. D) Both are chiefly carbon dioxide, but at Mars it can freeze as dry ice. E) Both are too hot for water to now exist as a liquid at the surface. 44) 45) The seasonal changes on Mars create: A) remarkable changes in size of the two dry ice polar caps. B) changes in the dark features noted from Earth by telescopes long ago. C) great changes in the barometric pressure as the atmosphere freezes and sublimes. D) huge dust storms that can enshroud the planet's disk. E) All of these are correct. 45) 7
46) Rank these magnetic fields, from weakest to strongest. A) The Moon, Mercury, Mars, Venus B) Venus, Mars, Mercury, Earth C) Earth, Venus, Mars, Mercury D) Mars, Venus, Earth, Mercury E) Mars, Mercury, Venus, Earth 46) 47) Mars' magnetic field is so weak because A) it spins much slower than Earth does. B) its core contains less iron than our own. C) it core may no longer be molten. D) Both B and C are probable. E) All of the above are correct. 47) 48) How many moons does Mars have? A) none B) one C) two D) three E) four 48) 49) Which statement about Mars' two moons is FALSE? A) Both are probably captured asteroids. B) Both are in retrograde orbits. C) Phobos revolves around Mars in less than a Martian day. D) Both are very dark, heavily cratered bodies. E) Phobos is larger than Deimos. 49) 50) What piece of evidence suggests that the martian moons did not form with Mars? A) They are both irregularly shaped and are heavily cratered. B) Their composition is significantly different from Mars and the terrestrial planets. C) They rotate synchronously, with one side tidally fixed toward Mars. D) They have circular orbits above the Martian equator. E) They have ages that are much younger than Mars. 50) 8