Astronomy Chapter 10

Rank these magnetic fields, from weakest to strongest. A) Venus, Mars, Mercury, Earth B) Mars, Mercury, Venus, Earth C) Earth, Venus, Mars, Mercury D) the Moon, Mercury, Mars, Venus E) Mars, Venus, Earth, Mercury

A

The largest difference between Mars's northern and southern hemispheres is that: A) the southern appears older, with more impact craters. B) the northern has all the outflows and must have been much hotter. C) the northern is higher overall, despite some high volcanoes in the south. D) the southern has a polar cap, but none ever forms in the north. E) the southern is much darker, with large mare-like basaltic lava flows.

A

What piece of evidence suggests that the Martian moons did NOT form with Mars? A) Their composition is significantly different from Mars and the terrestrial planets. B) They have ages that are much younger than Mars. C) They have circular orbits above the Martian equator. D) They rotate synchronously, with one side tidally fixed toward Mars. E) They are both irregularly shaped and are heavily cratered.

A

Which of the following characterizes a shield volcano? A) It sits above a hot spot in the planet's mantle. B) It is formed by moving tectonic plates. C) It will be smaller than cinder cones like Maxwell Mons on Venus. D) It erupts only briefly before subsiding forever. E) It cannot grow very large, for the plates are constantly moving.

A

Which of these is NOT now on the surface of Mars? A) Mars Global Surveyor B) Viking 1 C) Pathfinder D) Sojourner E) Spirit

A

Which statement about Mars's two moons is FALSE? A) Both are in retrograde orbits. B) Both rotate synchronously, keeping one face turned towards Mars. C) Phobos is larger than Deimos. D) Phobos revolves around Mars in less than a Martian day. E) Both are very dark, heavily cratered bodies.

A

If water caused the huge outflow channels on Mars, what was the most likely process that formed them? A) rainfall from the hydrosphere B) catastrophic but rare flooding C) annual melting of the seasonal ice caps D) large comets that struck Mars E) heat from the impact of the large asteroid that made Hellas

B

In 2014, Curiosity took rock samples that found: A) uranium compounds. B) organic compounds. C) that Mars's soil was no different than Earth's. D) only compounds of silicon, oxygen, and iron.

B

Mars is best viewed from Earth when it is at: A) perihelion. B) opposition. C) conjunction. D) aphelion. E) none of the above.

B

One of the most unexpected aspects of Mars's atmosphere is: A) that it is 95% carbon dioxide. B) that its troposphere changes altitude. C) that it is cloudless. D) that it contains water vapor clouds. E) that it has such a low density.

B

The first successful landers on the surface of Mars were: A) Mariners 4 and 5 in 1965. B) Vikings 1 and 2 in 1976. C) Voyagers 1 and 2 in 1979. D) Pathfinder and Sojourner in 1997. E) Spirit and Opportunity in 2004.

B

The runoff channels on Mars were most likely formed by: A) melting underground ice. B) catastrophic, but rare flooding. C) the annual melting of the polar ice caps. D) glaciers. E) rain that was part of a water cycle.

B

What property of Mars is responsible for producing the great heights of its volcanoes? A) Its cold temperatures allow the magma to freeze faster. B) Its thick crust can support larger peaks, and lower surface gravity does not pull them down as much as on Earth. C) Mars has more radioactive material than the Earth. D) Its higher surface gravity allows higher peaks to form. E) Its volcanoes are made of sulfur, like Io's.

B

Why is Mars red? A) Dust storms on the planet have blasted the planet so fiercely that the rocks have reddened. B) The iron in the surface rocks has been oxidized over time. C) Mercuric oxide is abundant and has a red tint. D) Sulfuric acid rain etched a reddish color into iron-rich surface rocks. E) The ancient volcanoes poured out vast plains of molten sulfur, much as on Io, which has now solidified and preserved the reddish color.

B

Why is the southern hemisphere of Mars believed to be older than the northern? A) The southern hemisphere is darker much like the lunar mare. B) The southern hemisphere is more heavily cratered. C) The northern hemisphere is higher, due to the Tharsis Bulge. D) The northern hemisphere leans more away from the Sun in winter. E) The south polar cap is much thicker than the north one.

B

Compare the atmospheres of Mars and Venus. A) Both are made of hydrogen and helium, like the jovians. B) Like Earth, nitrogen is the chief atmospheric gas. C) Both are chiefly carbon dioxide, but at Mars it can freeze as dry ice. D) Mars is rich in oxygen, like ours, accounting for its red surface. E) Both are too hot for water to now exist as a liquid at the surface.

C

Evidence of liquid water in Mars's distant past suggests that it had a substantial atmosphere compared to what it has presently. What happened to its water vapor? A) The carbon dioxide in its atmosphere dissolved in the water and combined with surface rocks. B) Its atmosphere was mostly hydrogen and helium. Mars's gravity is too weak to hold them. C) The water vapor has frozen out into the polar ice caps and permafrost as Mars has cooled. D) Mars initially had such a large greenhouse effect that the atmosphere became quite hot and slowly escaped. E) It has now all been lost in space, including the carbon dioxide and water vapor.

C

How does the axial tilt of Mars compare with our own? A) Like Jupiter, Mars always keeps its equator pointing at the Sun. B) It is about half our own, 12 degrees. C) It is almost identical to the Earth. D) Like Saturn, it's about 27 degrees. E) Like Uranus, it is 98 degrees and flopped over on its side.

C

How long is a day on Mars? A) 243 Earth days B) about 4.2 Earth days C) 24 hours, 36 minutes D) 23 hours, 56 minutes E) 9 hours, 55 minutes

C

How many moons does Mars have? A) none B) one C) two D) three E) four

C

That the Tharsis region on Mars has so few craters: A) proves tectonic activity is taking place. B) is due to the regions very low elevation. C) suggests it is the youngest region on the planet. D) suggests it is at the center of a particularly strong magnetic field. E) is due to annual flooding and water erosion.

C

The NASA mission(s) that landed on Mars in 1976 was (were) the: A) Voyagers. B) Magellan lander. C) Vikings 1 and 2. D) Venera 14. E) Galileo probe.

C

The largest and deepest impact basin found on Mars is: A) Olympus. B) Caloris. C) Hellas. D) Tharsis. E) Meridani.

C

The largest shield volcano yet discovered is: A) Maxwell Mons on Venus. B) Kilimanjaro on Earth. C) Olympus Mons on Mars. D) Prometheus on Io. E) Caloris on Mercury.

C

The most prominent feature of Mars observable from Earth is: A) its thick atmosphere. B) its two prominent moons. C) its bright polar caps. D) the large volcano Olympus Mons. E) the prominent feature, Valles Marineris.

C

Where on Mars did Mars Odyssey's gamma-ray spectrometer find evidence of subsurface ice? A) at the equator B) on Olympus Mons C) at high latitudes D) the Gale Crater E) Valles Marineris

C

Which is the correct size order, from smallest to largest? A) Mercury, Venus, Mars B) the Moon, Earth, Mars C) Mercury, Mars, Venus D) Mercury, the Moon, Mars E) Venus, Mars, Earth

C

Evidence for a permafrost layer of ice just a few meters below the surface of Mars include: A) outflow channels and ancient river deltas. B) "hydrated" chemical compounds found on surface rocks. C) carbonate rock layers that are in low abundance. D) "fluidized ejecta" craters. E) river channels and flood plains that look identical to such features on Earth.

D

Mars's magnetic field is most similar to: A) the Sun's magnetic field. B) Mercury's magnetic field. C) Earth's magnetic field. D) Earth's Moon's magnetic field. E) Jupiter's magnetic field.

D

Olympus Mons and Maxwell Mons are both: A) large features on the surface of Mars. B) features visible from Earth. C) dormant volcanoes. D) shield volcanoes. E) the two largest known volcanoes in the solar system.

D

One piece of evidence against the possibility of water on Mars is: A) the current lack of water on Mars. B) the fact that the polar ice caps are made of carbon dioxide ice. C) the volcanic activity on Mars. D) the few carbonate rock layers that would have formed on the bottoms of oceans. E) the "hydrated" chemical compounds found on surface rocks all over the planet.

D

The Curiosity rover has detected evidence of what kind(s) of chemical activity in Mars's soil? A) organic carbon chemistry B) helium and hydrogen C) photosynthesis D) water, sulfur and chlorine-containing minerals E) minerals containing sulfur or produced by reactions with sulfuric acid

D

The Tharsis Bulge on Mars is roughly the size of: A) Mexico. B) Asia. C) Texas. D) North America. E) New York City.

D

The deepest depression found on the surface of Mars is the: A) Mariannas Trench. B) Caloris basin. C) Valles Marineris rift. D) Hellas Basin of Mars. E) Mare Crisium.

D

The main constituent of the Martian atmosphere is: A) hydrogen. B) helium. C) methane. D) carbon dioxide. E) nitrogen

D

The most striking valley in the solar system is: A) the Grand Canyon in Arizona. B) Gwenivere on Venus. C) the Discovery Scarp of Mercury. D) Valles Marineris on Mars. E) Valhalla on Callisto.

D

Unlike Earth, Mars's seasons are affected (enhanced and diminished) by the distance between Mars and the Sun. This is because: A) Earth is closer to the Sun to begin with. B) an Earth year is shorter. C) Mars is tilted more on its axis than Earth is. D) the orbit of Mars is significantly more elliptical. E) Mars gets closer to the Sun than the Earth does.

D

Valles Marineris is the most striking example of a(n): A) impact crater. B) shield volcano. C) oceanic trench. D) rift valley. E) scarp

D

What causes the changing dark and light features visible on the Martian surface from Earth? A) seasonal growth of vegetation B) the flooding of the network of canals from seasonal polar ice melting C) lava fields, similar to those found on the Moon D) highly cratered and eroded areas that are frequently covered and uncovered by dust E) huge storms like those on Jupiter with winds that often reach speeds of hundreds of kilometers per hour

D

What is thought to be the reason that there are no small impact craters on Mars? A) Like Venus, Mars's atmosphere is too thick and these meteorites do not survive to make impacts on the surface. B) The surface of Mars is too young to have impact craters. C) Due to the gravitational pull of Mars's moons, most small meteoroids are deflected and never make it to the surface. D) The wind blows small dust particles, eroding the surface of Mars, erasing small impact craters faster than they can form. E) None of the above. Mars has lots of small impact craters.

D

What makes the view of Mars in the summer of 2003 so spectacular? A) There were huge dust storms that made the planet appear much brighter than usual. B) The feature known as Olympus Mons erupted spewing ash into the Martian atmosphere. C) Mars had an angular size comparable to the full Moon. D) Mars was both at perihelion and opposition, creating the perfect viewing conditions from Earth. E) Earth's atmosphere was amazingly clear everywhere for months making the view of spectacular Mars available to everyone.

D

What physical feature of Mars is atypical compared with the other terrestrial planets? A) its size B) its atmospheric content C) its surface composition D) its density E) its rotation rate

D

Where do the names for the moons of Mars (Phobos and Deimos) come from? A) the founders of Rome B) the twins depicted in the constellation Gemini C) the names of their discoverers D) the sons of Ares and Aphrodite E) the names of the dogs of Orion

D

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.

D

Why does Mars appear fainter than Venus, as seen from Earth? A) because of its red color B) because its two moons block the light from getting to Earth C) because it is often eclipsed by Jupiter D) because it is smaller, farther away and less reflective E) because it doesn't have water on its surface

D

Why was the summer of 2003 a fine time for Mars observers? A) The Mars Rovers returned live images from the surface. B) The skies were unusually clear and calm. C) Mars's north pole was tilted to face the Earth head-on. D) Mars was closer to us than it has been in over 50,000 years. E) Mars was even brighter than Venus for several weeks.

D

Is there evidence of life on Mars? A) Yes, at least at the time the Allen Hills Meteorite was formed, since it has fossils. B) Yes, but it is only in the form of microbes found by Viking landers. C) Yes, just found as fossils in the sedimentary rocks examined by Spirit. D) No, nothing suggesting life has ever been discovered. E) We have confusing and uncertain results to date.

E

Mars's magnetic field is so weak because: A) it spins much slower than Earth does. B) its core may no longer be molten. C) its core contains less iron than our own. D) All of the above are correct. E) Both B and C are probable.

E

Most of the dark regions on Mars visible from Earth are: A) features like the Valles Marineris. B) lava flows from active volcanoes. C) mountainous regions. D) the seasonal growth of vegetation on the planet. E) volcanic planes like the lunar maria.

E

The NASA lander which deployed the first rover, Sojourner, in 1997 was: A) Mars Rover. B) Global Surveyor. C) Viking 2. D) South Polar Lander. E) Pathfinder.

E

The difference between the Grand Canyon and the Valles Marineris is: A) the Grand Canyon was formed by water. B) the Valles Marineris is much larger than the Grand Canyon. C) the Valles Marineris has tectonic features surrounding it. D) the Valles Marineris has craters in and around it. E) all of the above.

E

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) moderate, about the flow rate of the Ohio River. C) fairly large, about the flow rate of the current Colorado River. D) significantly large, about the flow rate of the Amazon River. E) enormous, as much as 100 times the flow rate of the Amazon River.

E

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) huge dust storms that can enshroud the planet's disk. D) great changes in the barometric pressure as the atmosphere freezes and sublimes. E) All of these are correct.

E

Venus and Mars probably evolved differently from Earth because: A) they are slightly bigger than Earth. B) they are more massive than Earth. C) they have thicker atmospheres than Earth. D) they formed sooner than Earth. E) they orbit at different distances from the Sun

E

Why are Mars's seasons more extreme than those of the Earth? A) Mars's seas dried up long ago. B) Mars's axial tilt is slightly more than our 23.5 degrees. C) Mars's orbit is more eccentric than our almost circular one. D) Mars's weather is driven by evaporation from the polar ice in its summer. E) All of these contribute to the huge barometric changes that Mars experiences.

E

Atmospheric pressure on Mars is roughly half that of Earth's at sea level

False

Mars appears from Earth to go through all the phases like Venus.

False

Organic compounds have not been found on Mars, as of 2016.

False

Phobos and Deimos are probably captured comet nuclei

False

Running water continues to be the major erosive factor of Mars today.

False

The Mars Rovers found undisputed microfossils, proving life once existed on Mars.

False

The density of Mars is very similar to that of the other terrestrial planets.

False

The surface of Mars is surprisingly smooth and featureless

False

Because of its axial tilt and more elliptical orbit, Mars's polar caps change size even more than do the Earth's.

True

Mars has a weak magnetic field

True

Mars has an axial tilt more like the Earth's than any other planet in our solar system.

True

Mars undergoes seasons because of its eccentric orbit that carries it to widely different distances from the Sun, and because of its axial tilt which is similar to the Earth's.

True

Mars's atmosphere is strongly affected by the solar wind.

True

Mars's mass is only a tenth of the Earth's, and its density is also less than the Earth's.

True

Running water played a major role in shaping Mars in ancient times.

True

The atmosphere of Mars is composed of mostly carbon dioxide along with some nitrogen.

True

The low surface gravity helps Martian volcanoes grow to great heights.

True

The magnetic field of Mars was first detected by the Mars Global Surveyor.

True

The polar caps and dust storms of Mars can be seen with Earth-based amateur telescopes.

True

The seasonal polar caps on Mars, which grow and shrink over the year, are primarily carbon dioxide.

True

While Mars is half as big as the Earth in diameter, its surface gravity is only about 40% as strong as the 1 g we experience here on Earth.

True

While the red color of the Martian surface testifies to the presence of lots of iron, the weak magnetic field suggests it may not have a molten core anymore.

True