Deck 14: Cosmic Samples and the Origin of the Solar System

Question 1

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

Answer 1

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

Question 2

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
Section 14.3: Formation of the Solar System

Answer 2

organic materials, such as amino acids

Question 3

Astronomers call the vast, rotating cloud of vapor and dust from which the solar system formed:

A) the Oort Cloud
B) the Kuiper Belt
C) the proto-Sun
D) the solar nebula
E) Bayonne, New Jersey

Answer 3

the solar nebula

Question 4

Among solid worlds, which type of world is most likely to have significant geological activity?

A) those that are the smallest (and thus easiest to heat)
B) those that have strong magnetic fields
C) those that have a moon (satellite)
D) those that are the largest (and retain heat the best)
E) those that are farthest from the Sun

Question 5

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

Question 6

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

Question 7

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

Question 8

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

Question 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

Question 10

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

Question 11

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

Question 12

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
Section 14.2: Meteorites: Stones from Heaven

Question 13

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

Question 14

How do astronomers know that the age of the solar system is about 4.5 billion years old?

A) radioactive dating of all the rocks on Earth shows that age
B) they estimate that age from the number of comets that are still located in the Kuiper Belt
C) radioactive dating of the primitive meteorites indicates they have that age (since they are left-over building blocks of the solar system)
D) they estimate the date from the number of impact craters on the Earth
E) they have the warranty book for each planet, and it tells you when the unit was manufactured

Question 15

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

Question 16

The reason that worlds like the Earth are differentiated is that

A) the heat of the Sun vaporized much of their solid material early on
B) the heaviest chunks that hit early on were able to bore through solid rock to the center
C) the continuing impacts on a growing protoplanet eventually melted the entire body
D) large amounts of hydrogen and helium collect around such planets a little later in their history
E) planetesimals with different types of composition hit at different times, with the heaviest ones hitting first

Question 17

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

Question 18

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

A) meteor shower
B) radiant
C) fireball
D) meteorite which breaks into pieces when hitting the ground
E) trail so faint, there is no chance of our seeing it on the ground

Question 19

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

Question 20

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

Question 21

Which of the following planets does NOT have an atmosphere?

A) Earth
B) Venus
C) Jupiter
D) Neptune
E) you can't fool me: all of the above have an atmosphere

Question 22

The first technique that allowed astronomers to find exoplanets involved:

A) photographing the planets using infrared waves
B) looking for the decrease of light from the star during a transit of the planet across its disk
C) sending a very small spacecraft to the exoplanet to take close-up images
D) measuring changes in the radial velocity (Doppler shift) of the star caused by the pull of orbiting planets
E) simply taking a visible light photo of the planet around the nearest star; it wasn't that hard

Question 23

A type of planet that our surveys of exoplanets are revealing around other stars, but we don't have any examples of around the Sun are:

A) terrestrial planets
B) jovian (giant) planets
C) Super-Earth's
D) dwarf planets
E) you can't fool me, we have examples in the solar system of all the types of planets our exoplanet surveys are revealing

Question 24

One of the best proofs that our theory of how the solar system formed is correct is that astronomers now observe

A) Pluto's orbit, which is not in the plane (or disk) that the other planets orbit in
B) disks around other stars which show evidence of gaps where planets may be forming
C) planets that are called "hot Jupiters"
D) no water in the inner solar system
E) UFO's with alien astronomy textbooks inside, discussing the same theories

Question 25

Which planet in the solar system rotates the most slowly (has the longest "day")?

A) Venus
B) Uranus
C) Earth
D) Jupiter
E) Pluto

Question 26

Of the following planets which has NO satellites (moons)?

A) Earth
B) Venus
C) Jupiter
D) Pluto
E) Neptune

Question 27

The telescope in space that allowed astronomers to find thousands of exoplanets and exoplanet candidates by making very careful measurements during a planet transit was called:

A) Kepler
B) Voyager
C) Transitor
D) New Horizons
E) InSight

Question 28

Which planet in the solar system has the longest year (orbits the most slowly)?

A) Mercury
B) Uranus
C) Earth
D) Jupiter
E) Neptune

Question 29

At the beginning of the solar system's history, a ready supply of proto-planets or mini-planets crashed into the developing planets and each other - something astronomers call the "era of giant impacts." How long do astronomers estimate this era lasted?

A) only a few dozen years - it was over very quickly
B) about 100 million years (0.1 billion)
C) about two billion years
D) about four billion years (it only ended about half a billion years ago)
E) that era is not finished yet - giant impacts are still happening all over the solar system

Question 30

One of the most perplexing issues raised by the discovery of thousands of exoplanets is the existence of "hot Jupiters" - planets with the masses and compositions of Jupiter, but orbiting closer to their stars than Mercury does in our solar system. What is our best idea currently about how such "hot Jupiters" came to be?

A) each hot Jupiter came directly out of the star it now orbits and must be made of the exact same material at only slightly lower temperatures
B) hot Jupiters formed by the collision and merger of many terrestrial planets - these collisions heated them up
C) hot Jupiters formed in an asteroid belt and are made of countless asteroids that are hot
D) hot Jupiters formed further out in their star system, and then migrated inward somehow
E) hot Jupiters are artificial; they were made by super-advanced alien beings to make the universe more interesting
Section 14.5: Planetary Evolution

Question 31

For solid rocky worlds, a general rule is

A) the larger the world, the closer it is to the Sun
B) the smaller the world, the more likely it is to have an atmosphere
C) the larger the world, the slower it cools off and the more it will keep its internal heat
D) the smaller the world, the more likely it is to have a moon or moons
E) the shorter a world's year (time to orbit the Sun), the more likely it is to harbor life

Question 32

A key difference between the protoplanets that formed in the outer solar system and those that formed in the inner solar system was that

A) those in the inner solar system were much larger than those in the outer solar system
B) those in the outer solar system included far more metal and rock, and thus the outer planets could be denser
C) those in the outer solar system were in a place where ice, not just rock, condensed and thus could grow larger
D) those in the outer solar system did not have enough planetesimals nearby
E) you can't fool me, there were no differences between the inner and outer protoplanets; only the planets that finally formed are different.
Section 14.3: Comparison with Other Planetary Systems

Question 33

The atmosphere of Venus is mostly carbon dioxide, and the atmosphere of the Earth has water vapor. Why are these two gases absent in the atmosphere of the satellite around Saturn called Titan?

A) Titan's atmosphere was captured from the ring system of Saturn, and thus consists of small ice crystals
B) The energetic particles in the magnetosphere of Saturn have collided with and knocked away all the lighter gases in the atmosphere of Titan
C) There are life-forms on the surface of Titan which absorb carbon dioxide and water vapor as part of their life processes
D) Titan is so cold that carbon dioxide and water vapor freeze out
E) There is a runaway greenhouse effect on Titan
Extra: Some Review Questions Covering the Entire Solar System

Question 34

Astronomers now believe that the differences in composition among the planets reflect what characteristic in the early solar system

A) orbital speed
B) temperature
C) whether or not a planet had rings
D) the age of the material
E) none of the above

Question 35

Many worlds in the solar system show extensive impact cratering, dating back billions of years. Which of the following worlds does NOT show such cratering?

A) Our Moon
B) Callisto
C) Mercury
D) Saturn
E) Mars

Question 36

One of the best ways to learn more about a world is to have samples from its surface to analyze in our laboratories. From which of the following worlds do we NOT yet have a sample to analyze here on Earth?

A) Earth
B) the Moon
C) Mars
D) Venus
E) the asteroid Vesta

Question 37

Which of these worlds is the most active geologically?

A) Venus
B) Mars
C) Mercury
D) the Moon
E) all of the above are equally active these days

Question 38

Which of the following is NOT a way that Jovian planets can be distinguished from terrestrial planets?

A) their average density is lower
B) they are farther away from the Sun
C) they include much more gas and liquid
D) they are larger
E) they have many more craters from collisions that happened early in solar system history

Question 39

The reason that Olympus Mons, the tallest mountain on Mars, is taller than Mount Everest (the tallest mountain on Earth) is that:

A) the gravity on Mars is less, so a larger mass can support itself against its own weight
B) Mars has a much larger molten core than the Earth
C) there are no continental plates that move sideways on Mars, while there are such sliding motions on Earth
D) the Earth's Moon has a much stronger pull than the moons of Mars
E) more than one of the above

Question 40

The tallest mountain on a terrestrial world is:

A) Mt. Everest on Earth
B) Mt. Maxwell on Venus
C) the ring of mountains surrounding Copernicus crater on the Moon
D) the ice mountains on Titan
E) Olympus Mons (Mt. Olympus) on Mars

Question 41

Some of the early planetesimals that formed the solar system still survive today. Where would you find such planetesimals?

A) on the tallest mountains on Earth
B) in orbit around Mercury
C) in the asteroid and Kuiper belts
D) under the permafrost of Mars
E) you can't fool me, such planetesimals were swept up by the Sun long ago; none remain

Question 42

One of the following worlds has an orbit that actually crosses the orbit of another world. This "rude" world is:

A) Pluto's moon Charon
B) Pluto
C) Uranus
D) Venus
E) Io

Question 43

Which of the following worlds does NOT have a ring (as far as we know)?

A) Jupiter
B) Saturn
C) Venus
D) Uranus
E) Neptune

Question 44

Three kinds of worlds are round in our solar system. Which of the following is NOT a type of world that is typically round?

A) terrestrial planet
B) jovian planet
C) dwarf planet
D) minor planet (asteroid)
E) all of the above are round

Question 45

On which world besides the Earth could a human being step out of his spacecraft without a space suit and air tanks and be confident of surviving?

A) Mars
B) Venus
C) Europa
D) Titan
E) none of the above

Question 46

Which planet or dwarf planet in our solar system has the biggest moon relative to its own size? Not the biggest moon in terms of miles, but biggest compared to the size of the planet it orbits.

A) Jupiter
B) Neptune
C) Uranus
D) Saturn
E) Pluto