Astronomy Exam 4

7. Which of the following is NOT one of the largest moons in the Solar System?

Atlas

36. The largest and most massive of Saturn's rings is the

B ring

23. The same astronomer wrote extensively about canals on Mars and about the possibility of a ninth planet in our solar system. The observatory named after this astronomer is the:

Lowell observatory

11. In the far future, an entrepreneur with a large fleet of space ships decides to capture and bring to Earth some valuable asteroids. If at that time, there is a shortage of usable metals on Earth, what type of asteroids should his employees search for?

M-type

32. The mountains on Pluto are made of frozen water, which at Pluto temperatures, is as hard as rock. Pluto also has a smooth, round basin which could be thought of as a frozen sea. What material is in the basin (nicknamed Sputnik) likely to be made of?

Nitrogen

9. Callisto, the fourth moon of Jupiter's, takes 17 days to orbit Jupiter. If I stand on the surface of Callisto and see Jupiter high in the sky over my head, and then wait 8.5 Earth days in the same spot, where will I see Jupiter?

Overhead where it was before

2. Which planet has the biggest moon relative to its own size? Not the biggest moon in terms of kilometers, but the biggest as a percentage of the size of the planet it orbits.

Pluto

33. Which of the following worlds does NOT have a ring?

Pluto

37. Between 1992 and today, astronomers using large telescopes have discovered many icy pieces that orbit in the same region as the orbit of Pluto. These are believed to be members of the

The Kuiper belt

27. Which part of a comet is the DENSEST?

The nucleus

19. When the Dawn spacecraft explored the largest asteroid Ceres, it discovered white spots that appear to be salt and volcanic mountains made of water ice. This led astronomers to which of the following ideas: a. all asteroids are made of frozen water b. Ceres is really one of the terrestrial planets that got kicked out of its former orbit c. Ceres may have (or may have had) a liquid ocean under its crust d. Ceres formed from the breakup of a much larger body, a solid planet bigger than Jupiter e. The next thing to search for on Ceres are spots made of pepper

c. Ceres may have (or may have had) a liquid ocean under its crust

9. Why do astronomers today think that we have an asteroid belt and not a planet between Mars and Jupiter? a. a planet exploded and broke apart b. Io's volcanoes produced asteroids c. Jupiter's gravity prevented material in that zone from getting together d. the Sun's wind stops "blowing" there e. the solar system needed fashion accessories

c. Jupiter's gravity prevented material in that zone from getting together

35. Which of the following statements about Saturn's rings is TRUE? a. There is really only one ring, which looks unbroken from Earth b. The structure of the rings is completely independent of Saturn's moons c. The rings are made of billions and billions of individual "moonlets" (small chunks) d. The rings are made of particles no bigger than the particles that make up smoke e. If the rings were put on Earth, they would stretch from about New York to Boston

c. The rings are made of billions and billions of individual "moonlets" (small chunks)

12. How can astronomers measure the age of a meteorite that fell from the skies? a. Just like for planets, we measure the age by counting the number of craters on the meteorite b. Meteorites all contain metals and the metal conducts electricity better and better as it ages c. They measure the amount still left of radioactive materials in the meteorite, and how much has turned into decay products d. The age of a meteorite can be found from the angle at which it enters the Earth's atmosphere; so scientists can only get the ages of meteorites they observe falling e. There is no way to measure the age of any meteorites

c. They measure the amount still left of radioactive materials in the meteorite, and how much has turned into decay products

1. The typical meteor is a. about the size of a small one-family house b. made of evaporated ices c. a small solid particle, no bigger than a pea d. visible only from above the Earth's atmosphere e. the result of magnetic activity in the upper atmosphere of the Earth

c. a small solid particle, no bigger than a pea

7. If there are at least a million asteroids, how did spacecraft like Galileo survive their trip through the asteroid belt? a. NASA sends its spacecraft above and below the orbits of the asteroids in the belt to avoid collisions b. spacecraft use a magnetic repulsion tool to make sure asteroids do not come too close c. although there are many asteroids, they are widely spaced (there is lots of space between them) d. the known asteroids are typically less than a centimeter across, so they do not represent a danger to spacecraft e. you can't fool me, NASA has lost over a dozen spacecraft to collisions with asteroids

c. although there are many asteroids, they are widely spaced (there is lots of space between them)

2. The first asteroid to be discovered (which is also the largest one) is called

Ceres

26. Pluto's big satellite is called

Charon

6. The largest satellite (moon) in the solar system is:

Charon

24. Pluto was discovered through the patient searching of

Clyde Tombaugh

13. The satellite whose surface is characterized by a smooth icy crust with a complex network of cracks is:

Europa

3. When a chunk of cosmic material the size of a golf ball or a baseball hits the Earth's atmosphere it makes a

Fireball

5. The four large moons of Jupiter were first discovered by:

Galileo

16. The first asteroid confirmed to have a satellite (moon) was

Ida

15. The two asteroids from which close-up images and data have been returned by the Galileo spacecraft are:

Ida and Gaspra

11. What features are abundant on Callisto and Ganymede and almost absent on Europa and Io?

Impact craters

18. Which element plays the same role on Titan as water does on Earth (existing as gas, liquid, and solid)?

Methane

20. The lakes found in the north polar region of Titan are filled with liquid

Methane

21. The moon Triton orbits which of the planets?

Neptune

40. What makes the rings of Neptune different from those of other planets we know?

They are clumpy (bulging) in places

8. The satellite which has the thickest atmosphere (so thick that it's quite a surprise for a satellite) is:

Titan

39. The rings that most resemble Saturn's narrow F ring in the solar system are:

Uranus' rings

41. When two objects in orbit have periods of revolution that are simple ratios of each other (such as 1 to 2 or 1 to 3) we say that we have:

a resonance

29. The spacecraft that got the closest to the nucleus of Halley's Comet and sent back dramatic photographs of what the nucleus looked like was: a. Giotto b. Venera c. Pioneer d. Mariner 13 e. the Enterprise

a. Giotto

18. The Shoemaker-NEAR spacecraft explored two asteroids, Mathilde and Eros. A big difference between them is that: a. Mathilde appears to be pile of "rubble" (a collection of separate rocks) while Eros is solid b. Mathilde is a "real" asteroid, while Eros is a comet that has lost some of its ice c. Mathilde is always inside the orbit of the Earth, while Eros is always outside our planet's orbit d. Mathilde is going to impact the Earth, while Eros will never come near our planet e. you can't fool me, the two asteroids have exactly the same properties; that's why the same spacecraft could explore them

a. Mathilde appears to be pile of "rubble" (a collection of separate rocks) while Eros is solid

4. What do astronomers think is the origin of the many irregular moons around the outer planets (irregular meaning they are orbiting backwards and/or have eccentric orbits)? a. These moons were likely formed elsewhere and captured by the giant planets b. These moons are fragments of a much larger moon around each planet that exploded c. These moons were expelled by volcanoes on the surfaces of the giant planets d. These moons had an early interaction with the rings of the giant planets and were moved to strange orbits as a result e. Astronomers have no idea about why these irregular moons exist; it's a complete mystery

a. These moons were likely formed elsewhere and captured by the giant planets

40. Which of the following statements about the unusual object Chiron is FALSE? a. it is one of the largest asteroids, just a little smaller than Vesta b. its path around the Sun carries it from just inside Saturn's orbit almost out to Uranus' orbit c. it shows some characteristics of an asteroid and some characteristics of a comet d. in 1988, as it came closest to the Sun, it was seen to brighten by a factor of two e. its orbit does not appear to be stable

a. it is one of the largest asteroids, just a little smaller than Vesta

4. Chunks of solid material that survive passing through the Earth's atmosphere and are found on the Earth's surface are called a. meteorites b. asteroids c. meteors d. meteor showers e. comets

a. meteorites

13. The Murchison meteorite that was found in Australia in 1969 is important to scientists because it contained a. organic materials, such as amino acids b. more metal than any other meteorite c. large flecks of gold d. radioactive elements which we do not have on the Earth e. the decomposed bodies of small yellow aliens who were clearly intelligent

a. organic materials, such as amino acids

8. Some years some meteor showers, such as the Leonids, feature many more meteors than at other times. What is the cause of these "meteor storms"? a. the dust freed from some comets is clumpy and not evenly distributed along its orbit b. how many meteors we see in a given year depends one which side of the Sun we are on c. we get meteor storms at the same time and for the same reason we have more hurricanes on Earth d. meteor storms happen when Halley's Comet is near the Earth in its 76-year orbit e. no one has any idea about why meteor storms happen; they are a mystery

a. the dust freed from some comets is clumpy and not evenly distributed along its orbit

41. When larger fragments of Comet Shoemaker-Levy 9 crashed into Jupiter in 1994, a. they exploded in Jupiter's atmosphere, releasing energy equal to millions of megatons of TNT b. they changed the motion of Jupiter, making its orbit larger c. they produced vast plumes of material that changed the color of Jupiter's inner moons d. they reassured scientists on Earth that this kind of comet impact could NEVER happen to Earth e. they produced no visible effect whatsoever on the giant planet Jupiter

a. they exploded in Jupiter's atmosphere, releasing energy equal to millions of megatons of TNT

12. A baseball pitcher wants to impress his girl-friend with how strong his throwing arm is. On which of the following bodies would the pitcher be MOST likely to be able to throw a baseball (a fast ball) so fast it would actually go into orbit?

asteroid ida

0. In 2013, a small stony asteroid collided with the Earth above the Russian city of Chelyabinsk. What was the result? a. A large earthquake was felt all over Europe and Asia b. A fireball briefly brighter than the Sun could be seen in the sky c. It broke apart and large pieces of rock fell from the sky, killing thousands of innocent people d. The Earth's orbit around the Sun changed in a measurable way e. It burned up so high in the atmosphere, absolutely nothing could be felt or seen on the ground

b. A fireball briefly brighter than the Sun could be seen in the sky

7. If everything in the solar system is moving around, why do the Perseid meteors repeat regularly around August 11th or so? a. Because the Earth does not move relative to the meteor particles b. Because the Earth in its orbit intersects the same swarm of meteor particles at the same time each year c. Because the Perseids are not in space at all, but in the upper layers of the Earth's atmosphere d. Because August 11th is when the Sun's rays are the warmest, and thus tend to move the meteor particles toward us at the fastest speed e. Only astrologers can explain this regularity; astronomers do not understand it

b. Because the Earth in its orbit intersects the same swarm of meteor particles at the same time each year

28. The scientist who first proposed that comet nuclei were "dirty snowballs" was: a. Edmond Halley b. Fred Whipple c. Eugene Shoemaker d. Isaac Newton e. Jan Oort

b. Fred Whipple

23. According to our textbook, what is the best way to defend ourselves against an asteroid which is on course to collide with the Earth in 7 years? a. The only thing we could do would be to move some people to the Moon so they could survive b. If we do it early enough, we could explode something on or near the asteroid to deflect it slightly, so that years later it would then miss the Earth c. Asteroids are all rubble piles, so the only thing that would protect us would be a huge thermos-nuclear explosion that vaporizes the entire asteroid d. There is no problem, because all asteroid burn up by friction in the Earth's thick atmosphere e. There is no possible protection for us; if an asteroid is headed our way, we are all doomed

b. If we do it early enough, we could explode something on or near the asteroid to deflect it slightly, so that years later it would then miss the Earth

34. The rings of the outer planets consist of a. sheets of ice that stretch in round planes millions of miles wide around each planet b. billions of chunks (of various sizes) that all orbit the equator of each planet c. many large moons, about the size of Jupiter's moon Io, all crowded together d. subatomic charged particles, all kept in line by each planet's magnetic field e. millions of alien spacecraft, some of which occasionally make it to the Earth and pick up humans to experiment on

b. billions of chunks (of various sizes) that all orbit the equator of each planet

8. The fact that some asteroids cluster in what are called asteroid families is probably the result of: a. resonances with the jovian planets b. collisions which broke up larger bodies into a number of smaller ones c. comets which pass through the asteroid belt and attract asteroids to them d. strong magnetic fields found in some asteroids e. random chance

b. collisions which broke up larger bodies into a number of smaller ones

5. Short-period comets like Comet Halley a. return to the Oort Cloud during each of their orbits b. come back again and again at predictable intervals c. have a long tail visible during their entire orbit around the Sun d. can never be observed without a telescope e. you can't fool me, the only short-period comet we know is Halley

b. come back again and again at predictable intervals

6. When a periodic comet leaves its dusty debris behind in its orbit, the Earth can intercept this debris and a. show new impact craters b. have a meteor shower as the dust burns up c. lose ozone from its atmosphere d. speed up the orbit of the Moon e. have an increase in garbage bills from Alaska to New Zealand

b. have a meteor shower as the dust burns up

39. In addition to hundreds of smaller objects they have been discovering in the Kuiper Belt recently, astronomers were surprised to find a. clear evidence of the building blocks of life in their atmospheres and tails b. larger bodies, with sizes as big as Pluto (now called dwarf planets) c. objects whose orbits bring them as close to the Sun as Mars d. objects whose composition indicates that they are made mostly of stone and metal, not ice e. souvenirs from Earth's tourist attractions, such as Bayonne, New Jersey

b. larger bodies, with sizes as big as Pluto (now called dwarf planets)

2. Astronomers estimate that about 25 million meteors strike the Earth's atmosphere each day. How come we haven't run out of meteors in the long history of the Earth? a. meteors come from dust from the Earth's surface that winds have blown high into the atmosphere; the Earth is so big it has lots of dust b. meteors are pieces of dirt left over from the formation of our solar system and from old comets; there is a huge supply of small dirt particles from both sources c. meteors are caused by electrical sparking in the Earth's atmosphere and there is a lot of static electricity up there d. meteors have only been hitting the Earth's atmosphere recently; they are the result of human pollution of space e. this is an unsolved problem in astronomy that has a lot of astronomers mystified

b. meteors are pieces of dirt left over from the formation of our solar system and from old comets; there is a huge supply of small dirt particles from both sources

16. When the solar system was forming, the building blocks from which the protoplanets gathered together were the: a. gold, iron, and nickel atoms b. planetesimals (a few km to tens of km wide) c. giant accretion grains about the size of Mars d. extremely hot clouds of gas torn out of the Sun, which was already shining brilliantly e. pure water ice crystals, about the size of a snowflake

b. planetesimals (a few km to tens of km wide)

34. The large reservoir of comet nuclei far beyond Pluto, from which we believe new long-period comets come into the inner solar system, is called: a. the Lowell reservoir b. the Oort Cloud c. the Kohoutek Cloud d. the Alvarez belt e. Bayonne, New Jersey

b. the Oort Cloud

11. The ages of stony meteorites have been measured to be roughly equal to: a. the time since the last Ice Age on Earth b. the oldest ages we have measured for any bodies in the solar system c. the time since the great impact that killed the dinosaurs d. the time that has passed since the death of Julius Ceasar e. you can't fool me, we have no way of measuring the ages of stony meteorites

b. the oldest ages we have measured for any bodies in the solar system

24. Halley's Comet was given that name because Edmond Halley was a. the first person to ever see that comet b. the scientist who pointed out that the orbit of the comet was such that it should return every 76 years or so c. the chief scientist who designed the probe that flew by the comet d. the first person to be hurt by pieces falling off the comet e. prime minister of England at the time the comet was discovered

b. the scientist who pointed out that the orbit of the comet was such that it should return every 76 years or so

42. How does Saturn's F ring stay so thin (narrow), when the other rings are so wide? a. the further away from Saturn a ring is, the narrower it gets b. there are 2 shepherding satellites on either side of it c. Saturn's huge magnetic field keeps ice boulders from expanding d. the F ring is in the same orbit as the moon Enceladus e. we don't know the answer, because Saturn keeps its diet tips to itself

b. there are 2 shepherding satellites on either side of it

14. What evidence can you give that shows the surface of Jupiter's moon Europa must be relatively young? a. there are thousands of active volcanoes on Europa's surface b. we see very few craters compared to the surfaces of Callisto and Ganymede c. radioactive rocks from Europa that have been brought back to Earth by our probes show that Europa is a young moon d. the interior of Europa is made of metals like iron and nickel e. Europa was not orbiting Jupiter when Galileo observed its moons, but now it is

b. we see very few craters compared to the surfaces of Callisto and Ganymede

26. One of the key reasons that professional astronomers (as opposed to the public) are interested in comets is that they a. are beautiful to look at b. are always omens of disaster c. are icy pieces left over from the time that our solar system formed that can give us clues about that early time d. are pieces splintered off one of the giant planets, so they can provide us with samples of their composition e. are all visitors from other star systems, which can tell us about what conditions are like in distant reaches of the Milky Way Galaxy

c. are icy pieces left over from the time that our solar system formed that can give us clues about that early time

17. Astronomers have realized that the surface of Ida is older than the surface of Gaspra. How do they measure this? a. we have radioactive rock samples from each asteroid to analyze b. the surface composition (elements and compounds) can easily tell us the ages c. from counting craters on each asteroid's surface d. from the magnetic field of each body, which weakens with age e. it's purely a guess; astronomers have no way of really measuring the ages of these asteroids

c. from counting craters on each asteroid's surface

1. A main difference between asteroids and comets is that asteroids are mostly made of rock and comets are mostly made of a. metals b. carbon compounds c. ice d. vapor (gas) e. you can't fool me, astronomers don't really know what comets are made of

c. ice

3. One reason we know more about the surface composition of the asteroid Vesta than about most other members of the asteroid belt is that a. Vesta's volcanoes still spew out a lot of material that goes into orbit around Vesta b. Vesta's surface is made of water ice and is extremely reflective c. pieces of Vesta have landed on Earth as meteorites d. Vesta's orbit crosses the Earth's orbit roughly once a century e. Vesta's surface markings happen to resemble a human face and thus have intrigued astronomers ever since this large asteroid was discovered

c. pieces of Vesta have landed on Earth as meteorites

9. One way to find a new meteorite is to: a. patrol the block on which you live carefully each night for a few years b. look for a bright comet in the sky and look where its tail is pointing c. search the area beneath or close to the point where a bright fireball was seen to burn out d. look near the Earth's equator where our planet's magnetic attraction is the greatest e. taste the meatloaf in the college cafeteria late in the week

c. search the area beneath or close to the point where a bright fireball was seen to burn out

31. Our modern understanding of Pluto is that it is a member of a. the asteroid belt b. the giant planets c. the Kuiper Belt (of trans-Neptunian objects) d. the terrestrial planets e. no grouping within our solar system; it is completely one-of-a-kind

c. the Kuiper Belt (of trans-Neptunian objects)

5. According to astronomical tradition, who gets to suggest the name for a newly discovered asteroid? a. the president of the country of the discoverer b. a special committee of the U.N. set up for this purpose c. the discoverer of the asteroid d. a special committee in Italy, where the first asteroid was discovered e. authors of astronomy textbooks

c. the discoverer of the asteroid

16. What is the cause of its many volcanic/geyser-like eruptions on the moon Io? a. its surface is at the triple point of methane, where it can be gas/liquid/solid b. Jupiter's magnetic field causes huge bolts of lightning to hit Io and heat the surface c. the gravitational stress of being so close to Jupiter and its other large moons heats the Io's inside d. there is a metallic magnetic layer inside Io which is explosive e. inhabitants of Io are intercepting Earth TV transmissions; it's making them throw up

c. the gravitational stress of being so close to Jupiter and its other large moons heats the Io's inside

32. Comets change as they approach the Sun in their orbits. Which of the following statements about a comet approaching the Sun is FALSE? a. the solid water ice in a comet begins to evaporate just beyond the orbit of Mars b. comets close to the Sun can evaporate enough material to become as large or larger than Jupiter c. the gravity of the comet nucleus holds on to the evaporated material, and it all eventually freezes back into the nucleus d. when the ice evaporates, some dust frozen into the ice is freed up to join the comet's coma and tail e. the evaporation is not always even, but can occur in spurts (where jets of material are seen moving away from the comet nucleus)

c. the gravity of the comet nucleus holds on to the evaporated material, and it all eventually freezes back into the nucleus

22. Which of the following statements about the geysers on the moon Triton is true? a. they are caused by the impact of small comets on Triton's fragile surface b. the geysers are sulfur volcanoes which stick out of Triton's crust c. they involve plumes of nitrogen on the sunlit side of Triton d. they are caused by collisions with the rings of Neptune e. they are only visible when it is winter on Triton

c. they involve plumes of nitrogen on the sunlit side of Triton

10. Different asteroids reflect different percentages of the light falling on them. This is due to the fact that they have different:

compositions

12. The Galileo spacecraft measured that the moon Ganymede had a magnetic field, indicating that its interior was at least partly melted and warm. What do scientists think is the most likely reason for this? a. Ganymede is so far away from Jupiter, it is an independent world, and can compress its core without interference b. Ganymede has thousands of volcanoes, which then send material downward to heat up its interior c. Ganymede is a relatively small moon, and therefore much easier to heat up than its neighbor moons d. Ganymede is heated by tidal forces from Jupiter e. Scientists have no idea what causes the inner part of Ganymede to be warm; this is an unsolved mystery

d. Ganymede is heated by tidal forces from Jupiter

21. Which of the following statements about NEO's (Near Earth Objects) is TRUE? a. we have identified just about all NEO's with diameters greater than 1 km b. no NEO has passed closer to the Earth than the orbit of the Moon c. it is unlikely that any NEO's have hit the Earth during our planet's history d. NEO's can include both asteroids and comets that cross the Earth's orbit e. we are not able to obtain information about the shape or size of any of the NEO's at present

d. NEO's can include both asteroids and comets that cross the Earth's orbit

4. Two small moons in the solar system, known since the 19th century, turn out to be captured asteroids. These two moons are: a. Io and Europa around Jupiter b. Dione and Titan around Saturn c. the Earth's moon and antimoon d. Phobos and Deimos around Mars e. none of the above

d. Phobos and Deimos around Mars

33. Which of the following is NOT an accomplishment of the Rosetta mission to Comet Churyumov-Gerasimenko (C-G)? a. Rosetta matched orbits with Comet C-G and flew alongside b. Rosetta dropped the Philae lander on Comet C-G c. Rosetta took close-up images of Comet C-G and sent them back to Earth d. Rosetta took samples of the surface material of Comet C-G and sent them back to Earth e. Rosetta turned off the spacecraft systems to save power far from the Sun, and turned them back on as it got closer to the Sun

d. Rosetta took samples of the surface material of Comet C-G and sent them back to Earth

22. In 2012, NASA's Spaceguard Survey concluded that astronomers had now identified 90% of the asteroids with diameters greater than 1 km. How could astronomers know that they had reached this goal? a. Asteroids larger than 1 km are so rare and so big, they have always been easy to keep track of b. NASA is now able to keep track of everything in the solar system out to Pluto with great precision; nothing remains to be discovered in that region c. Most of the near-Earth objects that big are comets, and they all have big tails which are easy to see d. The people doing the survey began to find the same objects over again, indicating they were reaching the limits of their survey e. This was fake news; in fact, we can't ever know if we have found 90% of the larger near-Earth objects

d. The people doing the survey began to find the same objects over again, indicating they were reaching the limits of their survey

. How have astronomers learned what different asteroids are made of? a. The only way is to send a spacecraft to each asteroid and bring a chunk of it home b. They measure the x-rays that all asteroids give off c. They wait until the asteroid has a tail of gas behind it and measure that tail d. They examine the spectrum of the sunlight that reflects from the asteroid e. There is no way at the present time to know what asteroids are made of

d. They examine the spectrum of the sunlight that reflects from the asteroid

30. Which of the following statements about the tails of comets is FALSE? a. the tail always points away from the Sun b. some comets have both a gas tail and a dust tail c. the tail of a comet can sometimes be ahead of the comet in its orbit d. a comet always has a nice long tail, even when it is far from the Sun e. the Earth can pass through the tail of a comet without suffering any harm

d. a comet always has a nice long tail, even when it is far from the Sun

3. Why were asteroids not discovered until the 19th century? a. although asteroids are the same size as the planets, they are completely covered with dark dusty material, which means they reflect almost no light b. in their long looping orbits, it was not until the 19th century that an asteroid came close enough to the Earth to be detectable c. several asteroids collided with each other in early 1801, calling them to the attention of astronomers d. asteroids are generally small compared to planets and require a good telescope and patient searching to spot them e. only after Halley's work did astronomers think to look for the tails which allow us to spot an asteroid

d. asteroids are generally small compared to planets and require a good telescope and patient searching to spot them

10. When astronomers say that Ganymede is a differentiated body, they mean that it: a. has a northern hemisphere which is different from its southern hemisphere b. has more of the larger crater types than the smaller ones c. has a magnetic field that is not centered on its axis of rotation d. has a heavier core, surrounded by a lighter, icy mantle and crust e. has a color that is surprising among outer solar system satellites

d. has a heavier core, surrounded by a lighter, icy mantle and crust

28. Which of the following statements about Charon is FALSE? a. it takes the same amount of time to rotate and revolve b. it keeps the same face toward Pluto c. it takes the same time to go around Pluto as Pluto takes to rotate d. it has a significant atmosphere e. it has a retrograde orbit (revolves in a direction opposite to the sense that most satellites in the solar system revolve)

d. it has a significant atmosphere

35. Astronomers estimate that there may be a trillion (a thousand billion) comet nuclei orbiting beyond Pluto. Why then do we not see more comets in our skies? a. most comets are so small that millions pass by the Earth completely undetected b. most comets have orbits that only bring them inward as far as the orbit of Jupiter c. most comets collide with Jupiter each year and are thus not seen d. most comets remain in stable orbits beyond Pluto, only a few have their orbits disturbed and come into the inner solar system e. all the comets astronomers miss are the reason so many people report seeing UFO's

d. most comets remain in stable orbits beyond Pluto, only a few have their orbits disturbed and come into the inner solar system

6. If our estimates of the number of comets in every part of the solar system are correct, the total mass contained in comets must be: a. about the mass of Ceres, the largest asteroid b. about the mass of the Earth c. about the mass of the Moon d. on the order of the mass of all the planets put together e. since comets are mostly vapor, their total mass is less than that of the moons of Mars

d. on the order of the mass of all the planets put together

29. If I stood on the surface of Pluto, observing its big moon, I would see that moon: a. rise in the east b. rise in the west c. get smaller day by day d. remain in the same place in the sky e. Come on! Pluto has no moons!

d. remain in the same place in the sky

3. The majority of the moons orbiting the outer (jovian) planets are: a. large moons, roughly the size of Pluto or Mercury b. small moons orbiting in the same direction that their planet turns c. much warmer than the planet they orbit d. small moons orbiting in a retrograde direction (opposite to the direction their planet turns and orbits) e. not in good working order, since they were made in Bayonne, New Jersey

d. small moons orbiting in a retrograde direction (opposite to the direction their planet turns and orbits)

25. What method was used to discover Pluto in 1929-1930? a. look at irregularities (wobbles) in the motions of Uranus and Neptune b. use one of the first radio telescopes to measure cold radio waves from Pluto c. look for patterns in the orbits of the moons of Neptune to see in which direction Pluto would have escaped d. take pairs of photographs several days apart and "blink" them e. you can't fool me; Pluto was discovered by Galileo through one of his first telescopes

d. take pairs of photographs several days apart and "blink" them

15. Which of the following pieces of observational evidence does our modern "solar nebula" theory of the formation of the solar system NOT explain directly? a. the fact that all the planets revolve around the equator of the Sun in the same direction b. the difference in the composition of the terrestrial and jovian planets c. the ages of the oldest rocks on Earth, the Moon, and meteorites d. the plane of the orbit of Pluto e. the existence of comets in the outer solar system made mainly of frozen gases

d. the plane of the orbit of Pluto

19. For a while, after the space age began, astronomers did not know what the surface of Titan looks like, but today they do. Which of the following was NOT a method by which astronomers have learned about the surface of Titan? a. using instruments on the Huygens spacecraft to take pictures as it was descending b. using an infrared camera aboard Cassini to take images of the surface in infrared c. using a radar instrument to penetrate the smog in Titan's atmosphere d. using the Hubble Space Telescope in orbit to take a photo of Titan e. taking a photograph of the surface from a spacecraft that landed on Titan

d. using the Hubble Space Telescope in orbit to take a photo of Titan

5. A student in your class whom you kind-of like asks you come to watch a meteor shower. What exactly are you being invited to? a. something your mom would not approve of, involving streams of dirty water b. the closest approach of an active bright comet to the Earth c. a once-in-a-lifetime experience at the end of which you will be completely covered with dust particles from space d. watching the left-over dirt from a comet burn up by friction as the pieces hit the Earth's atmosphere e. something quite dangerous where you are likely to be hit when many larger rocks fall from above

d. watching the left-over dirt from a comet burn up by friction as the pieces hit the Earth's atmosphere

27. Two worlds in the outer solar system that seem remarkably similar to each other are: a. Titan and Ganymede b. Io and Europa c. Titan and Triton d. Callisto and Io e. Pluto and Triton

e. Pluto and Triton

38. The comet that broke into more than 20 pieces and then collided with Jupiter in 1994 was a. Giacobini-Zinner b. Kohoutek c. Halley's Comet d. Eros e. Shoemaker-Levy 9

e. Shoemaker-Levy 9

17. Which of the following is NOT a way that the moon Titan probably resembles the Earth? a. it has a thick atmosphere b. the main constituent of its atmosphere is nitrogen c. sunlight interacts with the chemicals on the moom to create a rich mix of organic molecules d. it has clouds in its atmosphere e. at its surface the temperature and pressure are just right for water to exist in all three phases (gas, liquid, and ice)

e. at its surface the temperature and pressure are just right for water to exist in all three phases (gas, liquid, and ice)

38. How were the rings of Uranus discovered? a. They were seen through a small telescope at the same time the planet was b. They were discovered with the Hubble Space Telescope c. They were discovered by the Voyager 2 spacecraft when it flew by Uranus d. Through the radio waves given off as they interact with the magnetic field e. by using the Kuiper Airborne Observatory (the telescope aboard an airplane) to observe Uranus moving in front of a distant star

e. by using the Kuiper Airborne Observatory (the telescope aboard an airplane) to observe Uranus moving in front of a distant star

6. More than 75% of the known asteroids: a. cross the Earth's orbit at least once as they revolve around the Sun b. are made of icy material that is highly reflective c. were once part of a planet as large as Jupiter d. lie farther out from the Sun than the orbit of Saturn e. can be found in a belt between Mars and Jupiter

e. can be found in a belt between Mars and Jupiter

30. The spacecraft that visited Pluto and send back our first images: a. was called New Horizons b. got a gravity boost from Jupiter to get it to Pluto faster c. used plutonium to keep it warm d. is returning to Earth in the 22nd century e. more than one of the above

e. more than one of the above

31. Comets get significantly brighter in our skies as they approach the Sun because a. they reflect more sunlight as they get closer to the source of light b. they get bigger as the ice evaporates c. they get closer to the Earth than when they were outside the orbit of Mars d. they move faster and faster e. more than one of the above

e. more than one of the above

14. Which of the following is not a characteristic that worlds in our solar system have in common: a. that the planets all revolve around the Sun in the same direction b. that most of the planets spin in the same direction that they revolve c. that many of the larger moons go around their planets in the same direction d. that the planets' orbits lie in roughly the same plane e. that all the planets have solid surfaces on which we can see impact craters

e. that all the planets have solid surfaces on which we can see impact craters

10. One region on Earth that has become a rich source of new meteorites in recent decades (including the meteorite from Mars that got famous because some scientists claimed they had found evidence for the building blocks of life on Mars) is: a. the Yucatan peninsula of Mexico b. Bayonne, New Jersey c. the Great Salt Lake d. Australia e. the Antarctic

e. the Antarctic

1. Which of the jovian planets does NOT have any satellites? a. Jupiter b. Saturn c. Uranus d. Neptune e. you can't fool me, all the jovian planets are accompanied by satellites

e. you can't fool me, all the jovian planets are accompanied by satellites

15. The world in the solar system that is most active volcanically is:

lo

37. Saturn's ring particles are composed mainly of:

water ice