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GEOL3405
Planetary Geology
200
Astronomy
07/18/2012

Additional Astronomy Flashcards

 


 

Cards

Term
The lithosphere of a planet is the layer that consists of
Definition
the rigid rocky material of the crust and uppermost portion of the mantle.
Term
The two most important processes in heating the interiors of the terrestrial worlds are:
Definition
(1) heat deposited by the process of formation;
(2) heat released by radioactive decay.
Term
What are the two geological features that appear to set Earth apart from all the other terrestrial worlds?
Definition
Plate tectonics and widespread erosion
Term
What observational evidence supports the idea that Mercury once shrank by some 20 kilometers in radius?
Definition
The presence of many long, tall cliffs
Term
How deep is an impact crater compared to its width?
Definition
10-20%
Term
What kind of thermal radiation does the Earth emit?
Definition
Infrared light
Term
Which of the following is the most basic definition of a greenhouse gas?
Definition
A gas that absorbs infrared light
Term
If the polar ice decreases, what would happen, and why?
Definition
Warming, because more sunlight is reflected
Term
What best describes how the greenhouse effect works?
Definition
A planet's surface absorbs visible sunlight and returns this absorbed energy to space as infrared light. Greenhouse gases slow the escape of this infrared radiation, which thereby heats the lower atmosphere.
Term
Which of the following is not an example of tectonics?
Definition
The stretching of the crust by underlying mantle convection

The formation of a cliff when the lithosphere shrinks

The slow movement of Earth's lithospheric plates
Term
Suppose you could float in space just a few meters above Saturn's rings. What would you see as you looked down on the rings?
Definition
countless icy particles, ranging in size from dust grains to large boulders
Term
The Huygens probe took numerous pictures as it descended to Titan's surface in 2005. What did the pictures show?
Definition
Features or erosion, including what appeared to be dry river valleys and lakebeds
Term
How do the size and mass of Jupiter's core compare to the size and mass of Earth?
Definition
It is about the same size but is 10 times more massive.
Term
How do the jovian planet interiors differ?
Definition
All have cores of about the same mass, but differ in the amount of surrounding hydrogen and helium.
Term
Why is Neptune denser than Saturn?
Definition
It has a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks.
Term
What is the most important in explaining the tremendous tidal heating that occurs on Io?
Definition
Io orbits Jupiter on an elliptical orbit, due to orbital resonances with other satellites.
Term
What is due to tidal forces?
Definition
the synchronous rotation of the Moon around Earth

the volcanos on Io (a moon of Jupiter)

the grooved terrain of Enceladus (a moon of Saturn)

the rings of Saturn
Term
Jupiter's colors come in part from its three layers of clouds. What are the primary constituent of one of Jupiter's cloud layers?
Definition
Clouds of ammonia
Clouds of ammonium hydrosulfide
Clouds of water
Term
What did the Huygens probe photograph as it landed on Titan?
Definition
hills, valleys and rivers
Term
Suppose there were no solar wind. How would the appearance of a comet in our inner solar system be different?
Definition
It would have only one tail instead of two.
Term
According to the nebular theory, how did the Kuiper belt form?
Definition
It is made of planetesimals that formed beyond Neptune's orbit and never accreted to form a planet.
Term
What do we mean by a mass extinction?
Definition
The extinction of a large fraction of the world's plant and animal species in a relatively short period of time
Term
What do we mean by a primitive meteorite?
Definition
A piece of rock that is essentially unchanged since it first condensed and accreted in the solar nebula some 4.6 billion years ago
Term
What is Pluto's moon Charon thought to have in common with our own Moon?
Definition
It probably formed as a result of a giant impact.
Term
Pluto is most like a
Definition
comet
Term
Among discovered meteorites, we have found some with all the following origins except
Definition
being a fragment from Comet Halley
Term
Where did comets that are now in the Oort cloud originally form?
Definition
near the jovian planets
Term
Hydrogen fusion in the Sun requires a temperature (in Kelvin) of
Definition
millions of degrees.
Term
The Sun's surface seethes and churns with a bubbling pattern. Why?
Definition
We are seeing hot gas rising and cool gas falling due to the convection that occurs beneath the surface.
Term
Which weighs more? Four protons or Two neutrons and two protons in a helium nucleus
Definition
Four protons
Term
The star Alpha Centauri A is the same type of star as the Sun, but its luminosity is about 1.6 times that of the Sun. What can we conclude?
Definition
Alpha Centauri A fuses hydrogen into helium in its core at a higher rate than our Sun
Term
Imagine that you are trying to stop neutrinos with a lead shield. How thick would you need to make this shield to ensure that it can stop a neutrino?
Definition
About 14 billion light years (the size of the observable universe)
Term
What is a way by which we can study the inside of the Sun?
Definition
We can probe the interior of the Sun by studying the vibrations in its photosphere.

We can study solar neutrinos.

We can make a computer model of the Sun's interior that allow us to predict the observable properties of the Sun.
Term
The overall result of the proton-proton chain is:
Definition
4 H becomes 1 He + energy
Term
What is true about globular clusters stars?
Definition
All stars in the cluster have approximately the same mass.
Term
An O-star has a hotter surface temperature than the Sun. Therefore, compared to the Sun,
Definition
its emission peaks in the blue part of the spectrum.
Term
If a star has a mass of 10 solar masses and a luminosity of 10,000 solar luminosities, how long is its lifetime? (The Sun's lifetime is 10 billion years.)
Definition
10 million years
Term
What are the standard units for luminosity?
Definition
Watts
Term
Which main sequence star has the lowest mass?

Hint: O.B.A.F.G.K.M.
Definition
M
Term
Ten parsecs is about ________.
Definition
32.6 light-years
Term
At the end of the life of a 1-solar-mass star, the remaining core of this star will be left behind as
Definition
a white dwarf made primarily of carbon and oxygen.
Term
The interstellar clouds called molecular clouds are ________.
Definition
the cool clouds in which stars form
Term
A spinning neutron star has been observed at the center of a ________.
Definition
supernova remnant
Term
What is a planetary nebula?
Definition
Gas ejected from a low-mass star in the final stage of its life
Term
What type of star spends the longest time as a protostar?

Hint: O.B.A.F.G.K.M.
Definition
M star
Term
Why are elements with even numbers of protons more abundant, on average, than elements with odd numbers of protons?
Definition
Because elements are mainly made in fusion reactions with helium nuclei
Term
A white dwarf is ________.
Definition
what most stars become when they die
Term
What is the basic definition of a black hole?
Definition
An object with gravity so strong that not even light can escape
Term
Imagine what would happen if Jupiter was suddenly replaced by a black hole with the same mass as Jupiter.
Definition
The orbits of the solar system would be unaffected (including Jupiter's)
Term
The orbits of the solar system would be unaffected (including Jupiter's)
Definition
carbon
Term
According to present understanding, a nova is caused by ________.
Definition
hydrogen fusion on the surface of a white dwarf
Term
If you could watch a time-lapse movie of the interstellar medium over hundreds of millions of years, what would you see?
Definition
Gas that is often moving at high speed, particularly after one or more supernovae, and constantly changing form between molecular clouds, atomic hydrogen, and hot, ionized bubbles and superbubbles.
Term
What is the diameter of the disk of the Milky Way?
Definition
100,000 light years
Term
When comparing halo stars to our Sun what is true?
Definition
Most stars in the halo are less luminous than the Sun.

Most stars in the halo contain a much lower percentage of heavy elements than the Sun.

Most stars in the halo have cooler surface temperatures than the Sun.
Term
How does the diameter of the disk of Milky Way Galaxy compare to its thickness?
Definition
The diameter is about 100 times as great as the thickness.
Term
Why do we believe that starburst galaxies represent a temporary stage in galaxy evolution?
Definition
Such galaxies form stars at such a high rate that they would have consumed all their gas long ago if they had always been forming stars at this high rate
Term
Why is a dense cloud more likely to produce an elliptical galaxy than a spiral galaxy?
Definition
The higher gas density forms stars more efficiently, so all the gas is converted into stars before a disk can form.
Term
What is the best way to determine a galaxy's redshift?
Definition
Take a spectrum of the galaxy, and measure the difference in wavelength of spectral lines from the wavelengths of those same lines as measured in the laboratory.
Term
When we say that a cluster of galaxies is acting as a gravitational lens, what do we mean?
Definition
It bends or distorts the light coming from galaxies located behind it.
Term
Based on current evidence, a supercluster is most likely to have formed in regions of space where ________.
Definition
the density of dark matter was slightly higher than average when the universe was very young
Term
Your cell phone friend left your house and is now driving 40 miles per hour, but she has been speeding up the whole time since she left your house, and has gone 10 miles. How long has she been driving?
Definition
Longer than 15 minutes
Term
Why do we call dark matter "dark"?
Definition
It emits no radiation that we have been able to detect.
Term
What are greenhouse gases?
Definition
gases that absorb infrared light
Term
What in its gaseous form is not a greenhouse gas?
Definition
Molecular nitrogen
Term
A planet is most likely to have tectonic activity if it has
Definition
high internal temperature.
Term
Which moon has a thick atmosphere made mostly of nitrogen?
Definition
Titan
Term
Why is Jupiter denser than Saturn?
Definition
The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn.
Term
What gas is not a significant ingredient of the jovian planet atmospheres?
Definition
Carbon dioxide
Term
What is the typical size of a comet's nucleus?
Definition
10 km
Term
Why aren't small asteroids spherical in shape?
Definition
The strength of gravity on small asteroids is less than the strength of the rock.
Term
Kirkwood gaps in the asteroid belt occur at distances where
Definition
the period of an orbiting asteroid would be a simple fraction (like 1/3 or 1/4) of Jupiter's orbital period.
Term
From center outward, which of the following lists the "layers" of the Sun in the correct order?
Definition
Core, radiation zone, convection zone, photosphere, chromosphere, corona
Term
Every second, the Sun converts about 600 million tons of hydrogen into 596 million tons of helium. The remaining 4 million tons of mass is ________.
Definition
converted to an amount of energy equal to 4 million tons times the speed of light squared
Term
Which stellar property has the greatest range in values?
Definition
luminosity
Term
What is Red Shifting?
Definition
Object is moving away from you
Term
What can be said about apparent and absolute magnitudes
Definition
The absolute magnitude of a star is another measure of its luminosity.

A star's absolute magnitude is the apparent magnitude it would have if it were at a distance of 10 parsecs from Earth.

A star with an apparent magnitude of 1 appears brighter than a star with an apparent magnitude of 2.

The magnitude system that we use now is based on a system used by the ancient Greeks over 2,000 years ago that classified stars by how bright they appeared.
Term
Where does gold (the element) come from?
Definition
It is produced during the supernova explosions of high-mass stars.
Term
Why is Supernova 1987A particularly important to astronomers?
Definition
It was the nearest supernova detected in nearly 400 years.
Term
A teaspoonful of white dwarf material on Earth would weigh
Definition
a few tons.
Term
When we see X-rays from an accretion disk in a binary system, we can't immediately tell whether the accretion disk surrounds a neutron star or a black hole. Suppose we then observe each of the following phenomena in this system. Which one would rule out the possibility of a black hole?
Definition
Intense X-ray bursts
Term
Where are most heavy elements made?
Definition
In stars and supernovae
Term
Most stars in the Milky Way's halo are ________.
Definition
very old
Term
Scale the Milky Way down to the size of a compact disc. What best describes the size, shape, and distance of the Andromeda Galaxy on the same scale?
Definition
a compact disk a few meters away
Term
What is one of the alternatives to the hypothesized existence of dark matter?
Definition
The theory of gravity is wrong.
Term
Based on its surface features, the most important event on Venus in the past billion years or so was ________.
Definition
a global "repaving" that erased essentially all the surface features that had existed earlier
Term
Why are there no impact craters on the surface of Io?
Definition
Io did have impact craters but they have all been buried in lava flows.
Term
What happened to the "Impactor" of the Deep Impact mission?
Definition
It created a small crater on the comet.
Term
How do we know how old the Sun is?
Definition
From ages of solar system meteorites, based on radioactive elements
Term
What terms are given to a pair of stars that we can determine are orbiting each other only by measuring their periodic Doppler shifts?
Definition
Spectroscopic binary
Term
You discover a binary star system in which one star is a 15 MSun main-sequence star and the other is a 10 MSun giant. How do we think that a star system such as this might have come to exist?
Definition
The giant must once have been the more massive star, but is now less massive because it transferred some of its mass to its companion.
Term
A paperclip with the density of a neutron star would weigh (on the Earth)
Definition
more than Mt. Everest.
Term
Harlow Shapley concluded that the Sun was not located at the center of the Milky Way Galaxy by
Definition
mapping the distribution of globular clusters in the galaxy.
Term
Which galaxy, as observed, has aged the most since it was born?
Definition
A nearby galaxy
Term
How do we know that galaxy clusters contain a lot of mass in the form of hot gas that fills spaces between individual galaxies?
Definition
We detect this gas with X-ray telescopes.
Term
Where is most of the water on Mars?
Definition
in its polar caps and subsurface ground ice
Term
What is most unlikely to be found on Titan?
Definition
Lakes of liquid water in the warmer equatorial regions
Term
Pluto is different from the Jovian planets in all of the following ways except which one?
Definition
It formed outside of the frost line in the solar nebula.
Term
How do we test our computer models for the interior of the Sun?
Definition
Comparing model predictions to how the Sun actually vibrates
Term
On a Hertzsprung-Russell diagram, where would you find stars that are cool and dim?
Definition
lower right
Term
What did Carl Sagan mean when he said that we are all "star stuff"?
Definition
that the carbon, oxygen, and other elements essential to life were created by nucleosynthesis in stellar cores
Term
True or False
The rise of life on the planet Earth some 4 billion years ago was made possible, in part, by the plentiful oxygen in Earth's early atmosphere.
Definition
False
Term
True or False
Higher temperatures make rocks weaker.
Definition
True
Term
True or False
There is no erosion of surface features on the Moon.
Definition
False
Term
True or False
The sky is blue because molecules in the atmosphere scatter blue light more effectively than red light.
Definition
True
Term
True or False
Earth outgassed as much carbon dioxide as Venus, but it is locked up in the oceans and rocks.
Definition
True
Term
True or False
The Huygens landing showed that the surface of Titan is as hard as a rock.
Definition
False
Term
True or False
Jupiter's Great Red Spot is a low-pressure storm like a hurricane on Earth.
Definition
False
Term
True or False
Some of the moons of the jovian planets have significant atmospheres.
Definition
True
Term
True or False
Titan's surface may contain lakes of liquid methane.
Definition
True
Term
True or False
Pluto has 3 known moons.
Definition
True
Term
True or False
No spacecraft has ever visited an asteroid or comet.
Definition
False
Term
True or False
Viewed from Pluto, the Sun would appear more than a thousand times fainter than on Earth.
Definition
True
Term
True or False
A spacecraft has captured and brought material to Earth from a comet.
Definition
True
Term
True or False
Sunspots are cooler than the surrounding region of the Sun's surface.
Definition
True
Term
True or False
The Sun generates energy primarily by nuclear fission.
Definition
False
Term
True or False
Gravitational equilibrium means that the surface and the core of the Sun are at the same pressure.
Definition
False
Term
True or False
All stars spend approximately the same amount of time on the main sequence.
Definition
False
Term
True or False
It is impossible for a star to have a negative apparent magnitude, such as -1.
Definition
False
Term
True or False
Spectral type, surface temperature, and color all describe the same basic characteristic of a star.
Definition
True
Term
True or False
Photographs of many young stars show long jets of material apparently being ejected from their poles.
Definition
True
Term
True or False
Our Sun will end its life in a planetary nebula and become a white dwarf.
Definition
True
Term
True or False
In any star cluster, stars with lower masses greatly outnumber those with higher masses.
Definition
True
Term
True or False
No visible light can escape a black hole, but things such as gamma rays, X-rays, and neutrinos can.
Definition
False
Term
True or False
Light escaping from white dwarfs will show a gravitational redshift.
Definition
True
Term
True or False
Open clusters and young stars are generally found only in the disk of the Milky Way and not in the halo.
Definition
True
Term
True or False
Most of the mass of the galaxy is located at the galactic center in the form of a massive black hole.
Definition
False
Term
True or False
All spiral galaxies have both a disk and spheroidal component to their stellar populations.
Definition
True
Term
True or False
A protogalactic cloud with very little angular momentum is more likely to form an elliptical galaxy than a spiral galaxy.
Definition
True
Term
True or False
Some galaxy clusters have not finished forming and are still attracting new members today.
Definition
True
Term
True or False
MACHOs are expected to be found only in the disk of the Milky Way, whereas WIMPs would be found only in the halo.
Definition
False
Term
True or False
Erosion is the most important geological process on Venus.
Definition
False
Term
True or False
Winter and summer differ in length on Mars because of its elliptical orbit.
Definition
True
Term
True or False
The water-ice particles forming Saturn's rings are frozen together into a thin sheet that rotates around Saturn like a solid body.
Definition
False
Term
True or False
A spacecraft traveling through the asteroid belt has a high risk of being destroyed through a collision.
Definition
False
Term
True or False
The chromosphere is the layer of the Sun that we see as its visible surface.
Definition
False
Term
True or False
A 10 solar mass star is about ten times more luminous than a 1 solar mass star.
Definition
False
Term
True or False
The helium fusion process works by fusing two helium nuclei into one beryllium nucleus.
Definition
False
Term
True or False
All massive-star supernovae leave behind black holes as remnants.
Definition
False
Term
True or False
The star-gas-star cycle will continue forever because stars are continually recycling gas.
Definition
False
Term
True or False
A protogalactic cloud with slow star formation is more likely to form a spiral galaxy than an elliptical galaxy.
Definition
True
Term
True or False
One possible ingredient of dark matter is known as WIMPs, or weakly interacting massive particles. Our best guess is that WIMPs probably are made of protons and neutrons.
Definition
False
Term
True or False
Without greenhouse gases, Earth's surface would be frozen over.
Definition
True
Term
True or False
Hydrogen exists as a gas, liquid, and solid within Jupiter.
Definition
True
Term
True or False
Pluto's surface features are completely unknown and await the visit by the New Horizon's spacecraft in 2015.
Definition
False
Term
True or False
The temperature of the Sun's core is about 20,000 K.
Definition
False
Term
True or False
The faintest visible stars to the naked eye have an apparent magnitude of about 6
Definition
True
Term
True or False
Although some photographs show what looks like jets of material near many young stars, we now know that these "jets" actually represent gas from the surrounding nebula that is falling onto the stars.
Definition
False
Term
True or False
More massive white dwarfs are smaller than less massive white dwarfs
Definition
True
Term
True or False
The Sun is located near the edge of our galaxy, approximately 100,000 light-years from the galactic center.
Definition
False
Term
True or False
Elliptical galaxies are more likely to be found in clusters than spiral galaxies.
Definition
True
Term
True or False
The rise of life on the planet Earth some 4 billion years ago was made possible, in part, by the plentiful oxygen in Earth's early atmosphere.
Definition
False
Term
True or False
Higher temperatures make rocks weaker.
Definition
True
Term
True or False
There is no erosion of surface features on the Moon.
Definition
False
Term
True or False
The sky is blue because molecules in the atmosphere scatter blue light more effectively than red light.
Definition
True
Term
True or False
Earth outgassed as much carbon dioxide as Venus, but it is locked up in the oceans and rocks.
Definition
True
Term
True or False
The Huygens landing showed that the surface of Titan is as hard as a rock.
Definition
False
Term
True or False
Jupiter's Great Red Spot is a low-pressure storm like a hurricane on Earth.
Definition
False
Term
True or False
Some of the moons of the jovian planets have significant atmospheres.
Definition
True
Term
True or False
Titan's surface may contain lakes of liquid methane.
Definition
True
Term
True or False
Pluto has 3 known moons.
Definition
True
Term
True or False
No spacecraft has ever visited an asteroid or comet.
Definition
False
Term
True or False
Viewed from Pluto, the Sun would appear more than a thousand times fainter than on Earth.
Definition
True
Term
True or False
A spacecraft has captured and brought material to Earth from a comet.
Definition
True
Term
True or False
Sunspots are cooler than the surrounding region of the Sun's surface.
Definition
True
Term
True or False
The Sun generates energy primarily by nuclear fission.
Definition
False
Term
True or False
Gravitational equilibrium means that the surface and the core of the Sun are at the same pressure.
Definition
False
Term
True or False
All stars spend approximately the same amount of time on the main sequence.
Definition
False
Term
True or False
It is impossible for a star to have a negative apparent magnitude, such as -1.
Definition
False
Term
True or False
Spectral type, surface temperature, and color all describe the same basic characteristic of a star.
Definition
True
Term
True or False
Photographs of many young stars show long jets of material apparently being ejected from their poles.
Definition
True
Term
True or False
Our Sun will end its life in a planetary nebula and become a white dwarf.
Definition
True
Term
True or False
In any star cluster, stars with lower masses greatly outnumber those with higher masses.
Definition
True
Term
True or False
No visible light can escape a black hole, but things such as gamma rays, X-rays, and neutrinos can.
Definition
False
Term
True or False
Light escaping from white dwarfs will show a gravitational redshift.
Definition
True
Term
True or False
Open clusters and young stars are generally found only in the disk of the Milky Way and not in the halo.
Definition
True
Term
True or False
Most of the mass of the galaxy is located at the galactic center in the form of a massive black hole.
Definition
False
Term
True or False
All spiral galaxies have both a disk and spheroidal component to their stellar populations.
Definition
True
Term
True or False
A protogalactic cloud with very little angular momentum is more likely to form an elliptical galaxy than a spiral galaxy.
Definition
True
Term
True or False
Some galaxy clusters have not finished forming and are still attracting new members today.
Definition
True
Term
True or False
MACHOs are expected to be found only in the disk of the Milky Way, whereas WIMPs would be found only in the halo.
Definition
False
Term
True or False
Erosion is the most important geological process on Venus.
Definition
False
Term
True or False
Winter and summer differ in length on Mars because of its elliptical orbit.
Definition
True
Term
True or False
The water-ice particles forming Saturn's rings are frozen together into a thin sheet that rotates around Saturn like a solid body.
Definition
False
Term
True or False
A spacecraft traveling through the asteroid belt has a high risk of being destroyed through a collision.
Definition
False
Term
True or False
The chromosphere is the layer of the Sun that we see as its visible surface.
Definition
False
Term
True or False
A 10 solar mass star is about ten times more luminous than a 1 solar mass star.
Definition
False
Term
True or False
The helium fusion process works by fusing two helium nuclei into one beryllium nucleus.
Definition
False
Term
True or False
All massive-star supernovae leave behind black holes as remnants.
Definition
False
Term
True or False
The star-gas-star cycle will continue forever because stars are continually recycling gas.
Definition
False
Term
True or False
A protogalactic cloud with slow star formation is more likely to form a spiral galaxy than an elliptical galaxy.
Definition
True
Term
True or False
One possible ingredient of dark matter is known as WIMPs, or weakly interacting massive particles. Our best guess is that WIMPs probably are made of protons and neutrons.
Definition
False
Term
True or False
Without greenhouse gases, Earth's surface would be frozen over.
Definition
True
Term
True or False
Hydrogen exists as a gas, liquid, and solid within Jupiter.
Definition
True
Term
True or False
Pluto's surface features are completely unknown and await the visit by the New Horizon's spacecraft in 2015.
Definition
False
Term
True or False
The temperature of the Sun's core is about 20,000 K.
Definition
False
Term
True or False
The faintest visible stars to the naked eye have an apparent magnitude of about 6
Definition
True
Term
True or False
Although some photographs show what looks like jets of material near many young stars, we now know that these "jets" actually represent gas from the surrounding nebula that is falling onto the stars.
Definition
False
Term
True or False
More massive white dwarfs are smaller than less massive white dwarfs
Definition
True
Term
True or False
The Sun is located near the edge of our galaxy, approximately 100,000 light-years from the galactic center.
Definition
False
Term
True or False
Elliptical galaxies are more likely to be found in clusters than spiral galaxies.
Definition
True