Astronomy Homework Questions (Ch. 6-14)

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: -the Alvarez belt -the Oort Cloud -the Kohoutek Cloud -the Lowell reservoir -the Kuiper belt

the Oort Cloud

The largest volcano on Mars is called: -Olympus Mons (Mt. Olympus) -Mount Maxwell -Hellas -the Red Spot -Mariner Valley

Olympus Mons (Mt. Olympus)

The Van Allen belt is a zone of small orbiting meteorites high above the Earth, which fall down from time to time -a region where industrial pollution has made a smoggy layer in the atmosphere -a piece of clothing worn by astronomers after they get their PhD's -a region where the ultraviolet light from the Sun is blocked from getting further down -a region of trapped charged particles in the Earth's magnetosphere

a region of trapped charged particles in the Earth's magnetosphere

The large, roughly circular, dark, and somewhat younger regions on the Moon are called: -rilles -maria -tectonic blobs -anti-cyclones -highlands

maria

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: -the Yucatan peninsula of Mexico -the Canadian tundra -the Great Salt Lake -the Antarctic -Australia

the Antarctic

Which theory of the Moon's origin do astronomers (and the evidence) favor: -the giant impact theory -the green cheese theory -the capture theory -the sister theory -the fission theory

the giant impact theory

What makes the rings of Neptune different from those of other planets we know? -they are much darker -they are clumpy (or bulging) in places -there is more than one ring in the system -they are much thinner -they have gaps and divisions in them

they are clumpy (or bulging) in places

Put the different planet characteristics into the appropriate box, either Mars or Venus.

Mars -has dust devils -U.S landed rovers there -has a runaway refridgerator effect -atmosphere's thinner than Earth's -rotates in about 24 hrs Venus -has clouds with sulfuric acid -Russia soft-landed probes that survived briefly -has a runaway greenhouse effect -atmosphere thicker than Earth's -rotates in 243 days

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

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

Place each description in the box that corresponds to the moon it applies to.

-Io: the moon volcanically active moon we know -Europa: it has a very smooth icy surface, crossed by narrow lines or cracks in the ice -Ganymede: the largest moon in out solar system -Titan: it is the only moon we know with a thick atmosphere the huygens lander touched down on this world -Enceladus: the moon has warm salt water geysers shooting out from one hemisphere -Triton: its very cold surface showed geysers of nitrogen gas when voyager flew by

At one time, astronomers thought that Mercury might rotate with the same period as it revolves around _________. During the 1960s, however, astronomers used _________ to determine that Mercury takes ________ to rotate. The period of rotation is ___ of the period of revolution, which turns out to be a stable ratio. Even more strange, the time it takes the Sun to return to the same position in Mercury's sky, turns out to be 176 days, which is equal to two Mercury _____.

At one time, astronomers thought that Mercury might rotate with the same period as it revolves around __the Sun__. During the 1960s, however, astronomers used __radar measurements__ to determine that Mercury takes __59 days__ to rotate. The period of rotation is __2/3__ of the period of revolution, which turns out to be a stable ratio. Even more strange, the time it takes the Sun to return to the same position in Mercury's sky, turns out to be 176 days, which is equal to two Mercury __years__.

Your friend, a graduate student in astronomy, is giving you a special tour of the local observatory. You notice that you are viewing the image from the big telescope from underneath the primary mirror; the beam of light has come through a small hole in the main mirror to an eyepiece below. This telescope uses what focusing arrangement? -prime focus -Newtonian focus -Cassegrain focus -Galilean focus -out of focus

Cassegrain focus

In the figure, please fill in the names of each layer of the Earth's atmosphere with the correct labels. Note that not all the provided labels will be used. -Ionosphere -Magnetosphere -Mesosphere -Protosphere -Startosphere -Troposphere

Ionosphere Mesosphere Stratosphere Troposphere

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? -C-type -S-type -primitive -M-type -none of these

M-type

Below is a list of planetary characteristics. Classify them in the two boxes by whether they belong with terrestrial planets or giant planets. -have solid surfaces -smaller planets -largely dominated by compounds of oxygen -largely dominated by compounds of hydrogen -have lower densities -have higiher densities -are further away from the Sun and cooler -have curcular craters from impacts on them -made mostly of rocks and metal -larger planets -have many moons -are closer to the Sun and warmer -made mostly of gases & liquids or ices

Terrestrial: -largely dominated by compounds of oxygen -smaller planets -have higher densities -have circular crates from impacts on them -made mostly of rocks and metal -have solid surfaces -are closer to the Sun and warmed Giant: -largely dominated by compounds of hydrogen -are further from the Sun and cooler -have lower densities -have many moons -made mostly of gases and liquids or ices -larger planets

On Earth, we can get the age of various parts of our planet by finding rocks that contain radioactive atoms. Which other world do we have a good number of rocks from to do this kind of age analysis? -The Moon -Jupiter -Halley's Comet -You can't fool me, there is no other world from which we have rocks -Venus

The Moon

The gradual drifting of the Earth's continents and the formation of new mountains and great rifts under the ocean can all be explained by the theory of ________________. These movements are powered by the process of _________ of heat in the Earth's __________. The segments of the Earth's crust pull apart along great __________ and are forced under one another in _______________.

The gradual drifting of the Earth's continents and the formation of new mountains and great rifts under the ocean can all be explained by the theory of __plate tectonics__. These movements are powered by the process of __convection__ of heat in the Earth's __mantle__. The segments of the Earth's crust pull apart along great __rift zones__ and are forced under one another in __subduction zones__.

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

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

Put the following events in the history of our solar system in chronological order, from the earliest to the most recent.

The solar nebula contracts under its own gravity A significant number of planetesimals form around the protosun Protoplanets undergo planetary differentiation Ice-rich comets bring frozen water to the cooling of Earth Plants on Earth begin to add a significant amount of oxygen to our atmosphere People on Earth read astronomy textbooks

Which of the following is NOT a correct statement about the rotation of Venus? -the rotation rate of Venus had to be determined from radar measurements -Venus rotates in roughly the same time period as Earth -Venus has the longest rotation period of any planet in the solar system -Venus rotates in a retrograde way (east to west) -the two definitions of a day (how long it takes for a star to return to the same position in the sky and how long it takes the Sun to return to the same position) do not agree on Venus

Venus rotates in roughly the same time period as Earth

Radioactive dating techniques have revealed that our Earth and Moon are approximately how old? -about 100 million years -about 6,000 years -about 2 million years -about 4.5 billion years -you can't fool me, we have no way of measuring ages as old as the Earth's

about 4.5 billion years

To overcome the problems that blur images and don't provide the best resolution from Earth, astronomers have started using flexible mirrors that change shape many times each second. This technique is called: -adaptive optics -peer review -focal length adjustment -light pollution -lowering resolution

adaptive optics

Why is an image recorded with a CCD better for astronomers than an image recorded on photographic film or plates? -CCD's are more efficient; more of the light is recorded and not wasted -CCD's allow more accurate measurements of the brightness of each part of the image -CCD's have digital output that can go directly to a computer -all of the above -none of the above

all of the above

The most important function of an astronomical telescope is to: -magnify (enlarge) celestial objects so we can see them clearly -pierce through the clouds so a cloudy night is not wasted -collect as much light as possible and bring it to a focus -bring distant objects closer by pulling on the light -enhance the violet colors of an object, which our eyes have trouble seeing

collect as much light as possible and bring it to a focus

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

come back again and again at predictable intervals

During the process of differentiation, -planets in a system separate so that terrestrial planets are all near each other and jovian planets are all near each other -the atmosphere of a planet changes from oxidized to reduced -heavier materials sink toward the centers of planets that are in a liquid or gas state -satellites separate from the parent planets and go into their own orbits -the faster planets move further out from the Sun

heavier materials sink toward the centers of planets that are in a liquid or gas state

In studying the surfaces of solid bodies in the solar system, astronomers have learned that the number of craters (per unit area): -is roughly proportional to the age of the surface we are examining -follows no discernible rules or relationships at all -is about the same on every world -is greater as you get closer to the Sun -is greater as you get further and further from the Sun

is roughly proportional to the age of the surface we are examining

Astronomers believe that Mars formed with a much thicker atmosphere than it has today. Where did this atmosphere go? -no one has any good theories about this; it is an unsolved mystery -it escaped into space (and some later froze out as Mars got cold) -it was drawn into the crust and mantle of Mars through the enormous cracks of the Mariner Valley canyon system -it was absorbed by the rocks on Mars, which are much more absorbent than on Earth -it is trapped in bubbles inside the rocks on the martian surface

it escaped into space (and some later froze out as Mars got cold)

An important way that scientists have been able to study the interior of the Earth is by: -there is no way we can study's the Earth's deep interior at the present time -studying the exterior, which is made of exactly the same material -measuring how seismic waves are transmitted through the Earth -digging deep trenches at the bottom of the ocean, which is a lot closer to the planet's center -using spacecraft that can detect strong radio waves coming from the center

measuring how seismic waves are transmitted through the Earth

Chunks of solid material that survive passing through the Earth's atmosphere and are found on the Earth's surface are called -comets -meteor showers -meteors -asteroids -meteorites

meteorites

The lakes found in the north polar region of Titan are filled with liquid -water -methane -nitrogen -you can't fool me, all the lakes on cold Titan are frozen solid; none are liquid -ammonia

methane

Which of the following statements about our Moon is FALSE? -it has no real atmosphere to speak of -on Earth, we can see all its sides in the course of a month as it goes around us -most of what we know about its geology is the result of the Apollo landings -its average density is less than that of the Earth (it seems to have fewer heavy materials) -its mass is less than that of the Earth

on Earth, we can see all its sides in the course of a month as it goes around us

A very wealthy donor decides to give a large sum of money to your college or university to build the world's largest visible-light gathering telescope. From an astronomical perspective, where would be the best location to put such a telescope? -in a dark spot right on the campus -on the west coast of the U.S. very close to sea level (a location like Seattle, for example) -close to a large city where there are many astronomers to use it -on a tall, dry mountain peak -wherever the donor wants to put it

on a tall, dry mountain peak

What is the cause of its many volcanic/geyser-like eruptions on the moon Io? -its surface is at the triple point of methane, where it can be gas/liquid/solid -Jupiter's magnetic field causes huge bolts of lightning to hit Io and heat the surface -there is a metallic magnetic layer inside Io which is explosive -radioactive decay in its interior keeps Io very warm -the gravitational stress of being so close to Jupiter and its other large moons heats Io's inside

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

What formation or formations are evidence that the planet Mercury may have shrunk (gotten a bit smaller) as it cooled? -the large basins in general -the long scarps or cliffs -the thin atmosphere emerging from inside the planet -lengthy cracks and deep canyons -the Caloris basin

the long scarps or cliffs

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

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

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

the plane of the orbit of Pluto

Which of the following is NOT a way that Venus resembles the Earth? -the thickness and pressure of its atmosphere -the surface gravity (which tells us how much we would weigh there) -its overall density -you can't fool me; Venus resembles Earth in all of these ways -its size (diameter)

the thickness and pressure of its atmosphere