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294 Cards in this Set
- Front
- Back
Absolute visual magnitude is |
the apparent magnitude of a star observed from a distance of 10 pc. |
|
____ are star-like objects that contain less than .08 solar masses an will never raise their core temperatures high enough that the proton-proton chain can begin. Other minor fusion reactions do occur in these objects. They fall in a gap between the low-mass M dwarf stars and the massive planets in which nuclear fusion never occurs. |
brown dwarf |
|
Most of the visible light we see coming from the sun originates from the |
photosphere |
|
Which of the following is evidence of an impact crater? |
overturned rocks, fluffy carbon, shocked quartz are possible |
|
Each element has its own set of characteristic absorption lines because |
electron energy levels differ for each element. |
|
The sunspot activity of the sun is cyclic, and shows periods of high sunspot activity approximately every |
11 years |
|
The absorption lines of a star are determined to be blue shifted, this means that they show a |
higher frequency and the star is moving toward us |
|
One hypothesis suggested to explain the uniform age of the surface of Venus is that |
Venus periodically goes through a catastrophic melting of the entire surface |
|
What characteristic of a star primarily determines its location on the main sequence? |
mass |
|
Comet Shoemaker-Levy 9 broke apart before impacting which body in our solar system? We were able to “see” the impact happen with spacecraft in the area. |
Jupiter |
|
The neutral hydrogen atom consists of |
one proton and one electron |
|
The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight would an observer see a continuous spectrum? |
1(the line directly pointing to the light bulb) |
|
The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight would an observer see an absorption spectrum? |
3(through the gas lamp and reaches to the bulb) |
|
The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight would an observer see an emission spectrum? |
2(through the gas cloud but doesn't make it to the bulb) |
|
The hydrogen in our solar system was created from subatomic particles in |
The Big Bang |
|
This part of a comet is very straight, and pointed directly away from the sun (due to the solar wind) |
ion tail |
|
The lowest energy level in an atom is |
the ground state |
|
What force(s) are responsible for the collapse of an interstellar cloud? |
gravity |
|
Interstellar gas clouds may collapse to form stars if they |
encounter a shock wave |
|
A ____ is a meteor which explodes before reaching the ground, although some fragments will hit the ground. |
bolide |
|
The sun has a surface temp. of approximately 5800 K. At what wavelength does the maximum energy radiated by the sun? |
520nm |
|
One star has a temperature of 10,000 K and another star has a temperature of 5,000 K. Compared to the cooler star, how much more energy per second will the hotter star radiate from each square meter of its surface? |
16 times |
|
A(n) ___ is a solar system object that enters Earth’s atmosphere and becomes very hot as it passes through the earth's atmosphere and does not survive to reach the surface. |
meteor |
|
In the diagram, which of the transitions would require the electron to absorb a photon with greatest energy (shortest wavelength)? |
Transition 4 (starts at nucleus and stops at 5th level) |
|
If the transition 3 is known to occur with an ultraviolet photon, then what kind of photon causes transition 4 to occur? |
ultraviolet photon |
|
A short period comet typically has a period of ____ and originated in the Kuiper belt. |
less than 200 years |
|
The brightness curve of binary stars helps us determine the period and the mass of those stars. Which type would a brightness curve help the most? |
eclipsing |
|
For observations of parallax angles of stars as seen from Earth, the baseline for |
2AU |
|
When geologists look at exposed rock layers around the world, they find evidence of the catastrophic event which probably caused the extinction of the dinosaurs. The period before the event is called the Cretaceous and the period after is called the Tertiary. The rock layer at the boundary between the two is about 65 million years old and is enriched in the element iridium. The name for this layer is called the |
K-T boundary |
|
Sunspots |
are cooler than their surroundings |
|
The sun’s magnetic field changes polarity every ___, so that the true solar magnetic cycle is ___. |
11 years, 22 years |
|
Protostars are difficult to observe because |
the protostar stage is very short, they are surrounded by cocoons of gas and dust, they radiate mainly infrared. |
|
The radiation emitted from a star has a maximum intensity at a wavelength of 300 nm. What is the likely temperature of this star? |
10,000 K |
|
Star A has m=2, and star B has m=7. Which star could be seen on a clear night in Santa Barbara without a telescope or binoculars? |
Star A only |
|
A 100W bulb, 2 meters from you is the same brightness as a ___ bulb held 1m away. |
25 |
|
The solar wind from our star is made up of |
hydrogen nuclei, helium nuclei, electrons |
|
The head of a comet is comprised of the |
Nucleus and coma |
|
Stars on the main sequence with the greatest mass |
are spectral type O stars |
|
The temperature of an object from which no heat energy can be extracted is |
0 K |
|
The two most abundant elements in the sun are |
hydrogen and helium |
|
Red giant stars are |
more luminous than the sun, larger in diameter than the sun, cooler than B stars, located above the main sequence stars in the H-R diagram. |
|
___ pushes gas and dust particles out of the solar nebula by the light from the sun. |
Radiation pressure |
|
A star which is half the mass of our sun is on the main sequence of an H-R diagram. Which of the following spectral classes would you expect it to be? |
K |
|
As a star begin to form the initial energy source that causes them to glow is from |
gravitational potential energy |
|
We know that giant stars are larger in diameter than the sun because |
they are more luminous but have about the same temperature |
|
Where on the above H-R diagram would you find a red dwarf? |
3 (highest in temp, and .1 in luminosity) |
|
Where on the H-R diagram would you find a white dwarf? |
1 (temperature 15,000, .01 in luminosity) |
|
A plot of the continuous spectra of five different stars is shown in the figure. Based on these spectra, which of the stars is the hottest? |
Star A (has the biggest curve) |
|
The coma of a comet is |
is formed be solid volatile ices sublimating into gases and a gas cloud around the comet nucleus |
|
If you compare two stars, |
the one with the lower absolute magnitude will always have the greater luminosity |
|
While on the main sequence a star’s primary energy source comes from |
nuclear fusion |
|
A long period comet can have an orbital period of 1 million years. Long period comets originate from the |
Oort cloud |
|
Emission nebulae are also called ___ because they are composed of ionized hydrogen. |
HII regions |
|
The lowest mass object that can initiate thermonuclear fusion of hydrogen has a mass of about |
.08 solar masses |
|
If two stars are emitting the same amount of light, the star that is further will appear |
dimmer |
|
The hydrogen lines in spectral type A stars |
are most narrow for supergiants |
|
Fluffy carbon is mostly made of |
carbon nanotubes |
|
An atom that is excited |
can emit a photon when the electron moves to a lower energy |
|
The sun’s magnetic field is evident in the looped shapes of |
prominences |
|
What observation made of other stars seems to suggest the solar nebula hypothesis is correct? |
Young stars are found to have hot disks that surround them |
|
Differential rotation of the sun |
the equatorial regions of the sun rotating more rapidly than the polar regions |
|
You are standing near a railroad track and a train is moving toward you at 60 mph and blowing its horn. What will you notice as the train moves past you? |
As the train approaches, the horn will sound higher in pitch than when the train is moving away.` |
|
Parallax would be easier to measure if |
Earth’s orbit was longer. |
|
Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be |
fainter and cooler than it really is |
|
In the H-R diagram, 90 percent of all stars are |
on the main sequence |
|
The tail of a comet points |
away from the sun |
|
From the data given, which star in the table has the greatest luminosity? |
58 Ori(least amount in the Mv){-6.0} |
|
From the data given, which star in the table would appear the faintest in the night sky? |
65 Tau (greatest mv) (4.2) |
|
From the data given, which star in the table has the greatest surface temperature? |
HR 4621 (spectral type B) |
|
Star A has m=3, and star B has m=8. Which star is brighter and how much brighter is it? |
Star A, 100X |
|
The youngest part of Earth’s crust are |
the midocean rifts |
|
There is a main sequence mass-luminosity relation because |
more massive stars support their large weight by making more energy |
|
The most common stars are |
lower mass (less luminous) main sequence stars. |
|
The iron in our solar system was created from smaller mass atomic nuclei in |
supernovas |
|
Condensation in the solar nebula probably led to the formation of icy grains beyond the present orbit of jupiter |
metallic grains near the present orbit of mercury and silicate grains near the present orbit of |
|
____ occurs when light travels out of a gravitational field, loses energy and its wavelength grows longer. |
a gravitational red shift |
|
Younger stars have more heavy elements because |
the heavy elements were made in previous generations of stars. |
|
Population II stars |
are primarily old low mass stars, and are located in globular clusters. |
|
How is the age of the galaxy determined? |
Finding the turnoff point in the H-R diagram of globular clusters. |
|
Which of the following can be used as distance indicators for galaxies (to figure out how far away galaxies are)? |
Only Cepheid Variables and Supernova Type I |
|
According to Hubble's Law, if Galaxy A is found to have a recessional velocity four times greater than Galaxy B, what can you say about their relative distance from Earth? |
Galaxy A is four times further away from Galaxy B |
|
A nova is almost always associated with |
a white dwarf in a close binary system. |
|
The H-R diagram of a young star cluster shows |
that low mass stars have not yet reached the main sequence yet. |
|
A white dwarf is composed of |
carbon and oxygen nuclei and degenerate electrons. |
|
What are the two longest stages in life of a one solar mass star? |
Main-sequence, white dwarf. |
|
Stars with masses between 0.4 Mo and 4 Mo |
undergo thermonuclear fusion of hydrogen and helium, but never get hot enough to ignite carbon. |
|
About how old is the earth compared to the age of the universe? |
about 1/3 as old |
|
A satellite is originally orbiting the Earth at a distance of 10,000 km from the center of the Earth. When the satellite moves to a new orbital distance of 20,000 km from the center of the Earth, how will the gravitational force change? |
the force of gravity will be 1/4 as large |
|
If you lived at the South Pole, when would it be daytime, and how long would the day last?HINT: Think about how the Earth is tilted (toward the sun or away from the sun). |
6-month day, from September to March |
|
Newton concluded that a force from the Earth had to act on the moon because |
a force is needed to accelerate the moon toward Earth away from straight-line motion. |
|
Retrograde motion, where a planet normally travels in one direction (prograde), then reverses for only a short period of time, |
is observable for all planets. |
|
Saturn's orbital distance is about 10 AU from the sun. What is the approximate orbital period of Saturn? Recall that Kepler's 3rd law is P2 = d3. |
32 years |
|
The eccentricity of a planet's orbit describes |
the deviation in shape when compared to a circle. |
|
The Milky Way Galaxy |
contains more than 200 billion stars. |
|
The __________ moon is visible on the western horizon a couple of hours before sunrise. |
waxing gibbous |
|
What conditions contribute to a long solar eclipse, such as the total solar eclipse of July 11, 1991 - one of the longest on record? (**Hint the recent Supermoon meant that the moon was at perigee**) |
in their elliptical orbits, the Moon is at perigee while Earth is at aphelion |
|
The large planetesimals would have grown faster than the smaller planetesimals because |
their stronger gravity would pull in more material |
|
Auroras around a body indicate that the body has |
magnetic field |
|
Which of the following objects is found in the Kuiper belt |
eris |
|
Protoplanets grew in size by |
collision and coalescence of planetesimal |
|
____ do not contain liquid metallic hydrogen because they are not massive enough. |
Uranus and Neptune |
|
Uranus's interior |
Doesn't contain any liquid metallic hydrogen because the pressure is so low. Has a small core of heavy elements(in the form of ice). |
|
The central regions of earth's core are solid because |
the pressure at the center raises the melting points |
|
This planet has the most extreme seasons of the planets in our solar system |
Uranus |
|
The ____ keeps venus hot because the atmosphere is predominantly carbon dioxide |
greenhouse effect |
|
The satellites discovered by galileo orbit the planet |
Jupiter |
|
The flow patterns found on the surface of mars and the number of craters on top of them suggest that the climate on mars was |
different billions of years ago |
|
The moons are mars are |
deimos and phobos |
|
The greenhouse effect occurs on earth because |
carbon dioxide is transparent to visible light and opaque to infrared radiation |
|
_____ pushed gas and dust particles out of the solar nebula by the light from the sun. |
Radiation pressure |
|
Europa has few craters because |
it has erased craters nearly as fast as they have forme |
|
Saturn's rings are |
in the plane of the planet's equator, composed of ice particles, inside the Roche limit |
|
_____ is an object what is most like the planetesimals that formed in the solar nebula. |
Asteroids |
|
Before the kepler mission, most of the bodies that were discovered from radial velocity consisted of very massive bodies which orbit close to their star. These planets are known |
hot Jupiters. |
|
____ is a satellite of pluto. |
Charon |
|
The old surfaces of icy satellites of jovian planets |
appear dark in color with many impact craters. |
|
A(n) _____ is a planet found orbiting around a star other than the sun. |
extrasolar planet |
|
____ does not have crustal plates on its surface. |
Jupiter |
|
The first solid grains of ____ formed in hot regions near the sun. Much farther from the sun the first grains (or rather flakes) of water ice also formed by a similar process as the close-in grains, condensation. |
iron |
|
Newton concluded that a force from the earth had to act on the moon because |
.. a force is needed to accelerate the moon toward earth away from straight-line motion. |
|
In terms of mass, Jupiter is made mostly of |
hydrogen and helium. |
|
Acceleration among the grains in the solar nebula would have been aided by |
static electricity. |
|
Why is it believed that the rings of Saturn could not have formed just as the planet itself formed? |
the rings are made of ice particles which would have been vaporized by the heat released as Saturn formed. |
|
Why did mars lose its atmosphere? |
the lack of magnetic field.. solar wind blew it away.. weaker gravitational force. |
|
After the first solid grains formed in our solar system, these particles could then grow by the process of ____. The collision and sticking of one particle with another to continue the formation of ______. Each of these has many atoms or molecule |
accretion, planetesimals |
|
_______ supports the idea that the martian crust is not divided into moving plates like those on earth. |
The size of Olympus mons, the lack of folded mountain chains, the lack of rift valleys outlining entire plates |
|
The _____ moon is visible on the western horizon a couple hours before sunrise. |
waxing gibbous |
|
Moon is no longer geologically active because |
it is much smaller in mass. |
|
The protective magnetic field of the earth is generated in this layer |
Solid metal core |
|
This moon of Saturn is nicknamed the death star because of its giant crater |
mimas |
|
The eccentricity of a planet's orbit describes the deviation in shape when compared to a |
circle. |
|
The planets all lie in nearly the same plane resulting in a disk-like structure for the solar system. This disk-like structure is believed |
to exist because the solar nebula from which the planets formed had a disk like structure. |
|
This nasa mission recently did a flyby of the dwarf planet pluto and took photos as well as a whole host of other data. |
Rosetta |
|
The kepler satellite mission uses which planet detecting technique? |
transit method |
|
Mercury has a surface which is older than venus. T or F |
T |
|
If you lived at the south pole….. when would it be daytime, and how long? |
6-month day, from September to December |
|
In contrast to the outer solid mantle, parts of the central region of earth's interior are thought to be fluid because______ cannot make it through those regions. |
S seismic waves |
|
_____ is the most geologically active of the Galilean satellites. |
Io |
|
_____ does not have a crustal plates on its surface. |
Jupiter |
|
Why is Saturn moon Titan able to retain an atmosphere? |
it has a large enough mass and is cold enough |
|
Why is saturn oblate? |
the rapid rotation of the planet flattens it |
|
Geology of venus appears to be dominated by |
volcanism |
|
One hypothesis suggested to explain the uniform age of the surface of venus |
venus periodically goes through a catastrophic melting of the entire surface. |
|
What type of geological activity is seen on Neptune’s moon triton? |
Geysers of liquid nitrogen are seen erupting from its surface |
|
Milky way galaxy contains _____ stars. |
more than 200 billion |
|
Belt and zone circulation |
occurs on Jupiter, occurs on Saturn, is caused by rising and sinking gases, is more obvious on Jupiter than on Saturn. The answer is all of the above. |
|
Both Jupiter and Saturn |
all of the above: have liquid metallic hydrogen in their interiors, emit more energy than they absorb from the sun, have belt and zone circulation, have rings |
|
Mars has a sufficient mass and a low enough temperature that water molecules could exist in its atmosphere as vapor. One reason mar’s atmosphere does not contain a significant amount of water vapor is that |
ultraviolet radiation breaks the water molecule into less massive particles that can escape |
|
Tycho Brahe's greatest contribution to astronomy was his |
discovery of three laws of motion |
|
Neap tides occur |
when the moon is first or third quarter |
|
The Copernican system was no more accurate than the Ptolemaic system in predicting the positions of the planets because |
the Copernican system used uniform circular motion. |
|
The _____ moon is visible near the eastern horizon a couple hours before sunrise |
waning crescent |
|
An epicycle is |
a small circle whose center is located on the circumference of another larger circle. |
|
What is the ratio of the light gathering power of a 3m telescope to that of a 1m telescope? |
9 to 1 |
|
which day of the week is associated with the planet mars? |
Tuesday |
|
In which position is the northern hemisphere experiencing the autumnal equinox? |
b |
|
Why did galileo's observations of moons orbiting Jupiter disagree with geocentric model of the universe of the moons? |
did not appear to orbit the earth |
|
Newton's third law |
you cannot move yourself. As you walk along the ground, your feet push back on the ground and the ground in turn pushes you forward. the size of the force you feel is the same as the force you push against the ground, but the direction is the opposite. |
|
Gamma rays, ultraviolet light, and x-rays have wavelengths that are |
shorter than visible light. |
|
Tycho did not accept a _____ of the universe. |
heliocentric model |
|
First quarter moon rises at |
noon. |
|
x-ray telescopes must be used |
above earth's atmosphere |
|
synodic period is |
29.5 day long, which is the period of time for the moon to complete a cycle of the lunar phases |
|
______ of mars can best be explained as earth overtaking and passing mars. |
retrograde motion |
|
Ultraviolet radiation is absorbed by ozone in earth's atmosphere that is located between 20km and 40 km above earth's surface. Therefore, telescopes to observe this radiation must be placed |
in space. |
|
light gathering power |
biggest diameter and biggest focal length |
|
kepler's 3rd law of planetary motion |
the larger the orbit, the longer its orbital period |
|
Chromatic aberrations occurs |
in a refracting telescope when different colors of light do not focus at the same point |
|
in a reflecting telescope the objective is |
a mirror |
|
spring tides occur at |
new moon and full moon |
|
The very long baseline interferometer is |
a set of radio telescopes linked together electronically to provide very high resolution |
|
total lunar eclipses always occur at at the time of |
a full moon |
|
the sun is |
visible by its own light emissions 1 au from earth and a star which generates its own energy |
|
The sidereal period of the moon is |
all of the above.. 27.32, and is the period of time for the moon to orbit earth once with respect to the stars |
|
A new generation of ground based telescopes is currently being built that overcomes the limitations of the older large telescopes. Some of these new telescopes. |
Use active optics to control the shape of the mirror. Use segmented mirrors and use mirrors that are very thin |
|
A telescope whose objective is a lens and contains no mirrors is a |
refracting telescopes |
|
A solar or lunar eclipse will occur when |
the sun is near the line of nodes of the moon and the moon is new or full. |
|
Galileo’s observations of a complete set of phases of Venus proved that |
Venus orbited the sun |
|
The energy of a photon is directly proportional to the |
frequency |
|
following distances in order from SMALLEST TO LARGEST. (AU, yard, LY, kilometer) |
yard, kilometer, AU, LY |
|
What is the longest wavelength of light that can be seen with the human eye? |
700 nm |
|
Precession of the rotation axis is caused by? |
the torque of gravity from the sun and moon on earth's equatorial bulge |
|
Infrared radiation is absorbed by water in earth's atmosphere and requires that telescopes for observing at these wavelengths be placed |
on mountains tops or in space |
|
A satellite is originally orbiting the earth at a distance of 10,000 km from the center of the earth. When the satellite moves to a new orbital distance of 20,000 km from the center of the earth, how will the gravitational force change? |
the force of gravity will be ¼ as large |
|
Kepler's second law |
implies that a planet should move at its greatest speed when it is closest to the sun |
|
A comet is found in a highly elliptical orbit to have a semi-major axis (like orbital radius) equal to one AU. According to kepler's 3rd law what would be the sidereal period of this comet |
it will be one year |
|
Radio telescopes are important in astronomy because |
they can detect cool hydrogen |
|
Retrograde motion is observable from |
all planets |
|
According to Newtonian mechanics, a force must be acting on a body if the body changes its |
velocity |
|
How is a planet different than a star? |
Planets reflect light while stars produce their own light |
|
During the month of June, the north axis of earth points towards Polaris but during the month of December it points |
still towards Polaris |
|
Kepler's first law of planetary motion |
implies that the planets move in elliptical orbits around the sun |
|
Darkest part of the earth's shadow is |
the umbra |
|
the diameter of the earth is approx. |
12800 km |
|
A total solar eclipse always occur at which phase of the moon? |
New moon |
|
parallax is |
the apparent motion of an object due to the motion of the observer |
|
The mass of an object is a measure of the amount of matter it contains, on the other hand, weight is |
a measure of the gravitational force on an object |
|
the orbit of the planet Saturn is an ellipse with the sun at one focus. What is locate at the other focus? |
nothing |
|
an observer in the northern hemisphere watches the sky for several hours. Due to the motion of earth, this observer notices that the stars near the north celestial pole appear to move ____ around the celestial pole. |
counterclockwise |
|
Gamma rays is |
a type of electromagnetic radiation that has the greatest energy. |
|
photons of ___ light have a greater energy than photons of ____ light |
blue, green |
|
Luminosity is dependent on |
the size of the star, give more light in total but be as cool. |
|
Two light bulbs are the same but if you made one a lot bigger, |
the brightness doesn’t change but the bigger one is luminous because it is bigger in radius |
|
A nova |
(a sudden and temporary brightening of a star making it appear as a new star in the sky, evidently caused by an explosion of nuclear fuel on the surface of a white dwarf) |
|
The theory that Mercury shrank slightly when it was young has been proposed to explain |
lobate scarps |
|
The greenhouse effect keeps Venus hot because |
the atmosphere is predominantly carbon dioxide |
|
Coronae on Venus are believed to be |
caused by rising convection currents in the interior of Venus. |
|
Mars has a sufficient mass and a low temperature that water molecules could exist in its atmosphere as vapor. One reason Mar's atmosphere does not contain a significant amount of water vapor is that |
Ultraviolet radiation breaks the water molecule into less massive particles that can escape. |
|
The extreme size of volcanoes on Mars indicate that |
Mars has a much thicker crust on Earth and large moving plates have not formed on Mars. |
|
The Roche Limit is the |
distance from a planet within which a satellite cannot hold itself together. |
|
Planets were first detected around distant stars by the Doppler effect. The Doppler effect causes light from a body moving toward us to be shifted to... (frequency: longer, lower, higher) |
higher frequency |
|
If light takes 8 minutes to travel from the sun to Earth and over 4 hours to travel from the sun to the planet Neptune, what is the distance from the sun to Neptune? |
30 AU |
|
If the distance to the nearest star is 4.2 light-years, then |
the light we see left the star 4.2 years ago. |
|
The radius of the moon's orbit is about ____ times larger than the radius of Earth. |
60 |
|
A total lunar eclipse is |
visible to all observers on the side of Earth from which the moon would be visible at that time. |
|
An observer in the Northern Hemisphere watches the sky for several hours. Due to the motion of Earth, this observer notices that the stars near the north celestial pole appear to move |
counter clockwise around the celestial pole. |
|
Seen from the northern latitudes (mid-northern hemisphere), the star Polaris |
is always above the northern horizon. |
|
The apparent visual magnitude of a star is a measure of the star's |
intensity. |
|
The lowest amount of solar energy per square meter is incident upon the surface of Earth in the northern hemisphere on or about |
December 21, the winter solstice. |
|
The moon has an angular diameter of 0.5°. What is the moon's angular diameter in minutes of arc? |
30 |
|
The point in Earth's orbit where Earth is farthest from the sun is known as |
aphelion. |
|
The saros cycle |
all of the above -was used in ancient times to predict eclipses. -is 18 years, 11 1/3 days long. -comes from a Greek word that means repetition. |
|
The __________ moon is visible on the western horizon a couple of hours after sunrise. |
waning gibbous |
|
When will the full moon be highest above the southern horizon for an observer in the Northern Hemisphere? **Hint: the full moon is always "opposite the sun" when seen from the Earth. |
at midnight near the winter solstice |
|
Which of the following historical characters developed a mathematically based geocentric theory of the earth at the center of the cosmos? |
Ptolemy |
|
As a bird flies, its wings push air downwards. At the same time, the air also pushes the bird upwards. The size of the force on the air equals the size of the force on the bird, and the direction of the force on the air (downwards) is opposite the direction of the force on the bird (upwards). This is an example of which of Newton's three laws of motion? |
Newton's third law |
|
Which of the following historical characters was first to propose that the sun was at the center of the cosmos? |
Nicolaus Copernicus |
|
Galileo Galilei |
All of the above greatly improved the design of the telescope. -observed the phases of Venus. -observed the moons of Jupiter. -discovered sunspots. |
|
Newtons law of universal gravitation states that any two bodies in the universe attract each other with a force that is __________ proportional to the product of their masses and __________ proportional to the square of the distance between them. |
directly; inversely |
|
Tycho Brahe's greatest contribution to astronomy was |
his 20 years of careful observations of the planets. |
|
Ptolemys model of the universe |
contained epicycles. |
|
If a planet were orbiting the Sun in an orbit three times as far as its current orbit, how many times longer would it take the planet to go around the sun, as compared to its current rate of revolution? |
About 5.2 |
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Ptolemy's purpose in using epicycles to explain the motion of the planets in the night sky was to account for |
retrograde motion. |
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Which of Kepler’s laws of planetary motion states that the orbit of every planet is an ellipse with the sun at one of the two foci? |
Kepler's first law |
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A ____ has a few million light sensitive diodes in an array typically about a half-inch square. |
charge-coupled device |
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Astronomers build telescopes on tops of mountains because |
there is less air to dim the light and the seeing is better. |
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Chromatic aberration occurs in a ____ telescope when ____. |
refracting; different colors of light do not focus at the same point. |
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In which way does a photon of blue light NOT differ from a photon of red light? |
speed |
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The energy of a photon |
is inversely proportional to the wavelength of the light. is directly proportional to the frequency of the light |
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The technique of connecting multiple telescopes together to combine the images from each telescope is known as |
interferometry. |
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What is the ratio of the light gathering power of a 10 m telescope to that of a 1 m telescope? |
100 to 1 |
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____ is absorbed by water in Earth's atmosphere and requires that telescopes for observing at these wavelengths be placed on mountain tops or in space. |
Infrared radiation |
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How rapidly a planet loses its atmosphere depends on the planet's |
temperature, atmospheric composition, escape velocity (determined by mass and radius) |
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In the development of a terrestrial planet, the stage of ____ when dense material settled to the core and less dense to the outer parts. |
differentiation |
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Motion of the plates of Earth's crust is thought to be due to |
convection from the hot interior. |
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That the moon has no magnetic field implies that |
the moon's core contains little if any molten iron. |
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The greenhouse effect produces excess heat in a planet's atmosphere by |
trapping infrared radiation from escaping into space. |
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The Himalayan Mountains are rugged, jagged peaks and the Appalachians are smooth and rolling. Why is there a difference? |
The Appalachians are much older and have been smoothed by erosion. |
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The lunar maria are |
the lava plains of the lunar lowlands. |
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What do astronomers generally believe about the origin of Mars' moons? |
They formed elsewhere and were captured at a later time. |
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Which hypothesis concerning the formation of the Moon makes predictions that best fit the observed lunar data? |
The large impact hypothesis |
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Which of the terrestrial planets has the most difficult time retaining an atmosphere? |
Mercury |
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Why does Mars have seasons similar to the Earth? |
Mars' rotational axis is tilted relative to its orbit like the Earth's. |
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____ is a very long and deep canyon on Mars. |
Valles Marineris |
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At Jupiter's very center is probably a small core of |
heavy element (molten rock and iron) core |
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Some narrow rings of Saturn are seen in space probe photos to be caused by |
small shepherd moons that orbit inside and outside the rings |
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The magnetic fields of Uranus and Neptune are peculiar in that they are |
highly inclined to their planet's axis of rotation. |
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The reddish particles in Jupiter's ring are less than 1 percent as reflective as Saturn's whiter particles. Saturn's ring particles are thought to be ____while Jupiters are thought to be ______ |
icy; rocky |
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The ____ of a planet is the region around the planet where the magnetic field is able to deflect the solar wind and other charged particles. |
magnetosphere |
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Uranus and Neptune appear blue or blue-green because |
traces of methane in their atmospheres absorb red light very efficiently. |
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Uranus and Neptune do not contain liquid metallic hydrogen because they |
are not massive enough. |
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What causes the geological activity seen on some of the inner moons of Jupiter? |
Tidal friction as a result of being so close Jupiter heats their interiors. |
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A newly formed planet or large asteroid becomes molten due to ______. |
decay of radioactive element isotopes and the last infalling objects |
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If a star is found with five planets orbiting it, and a process like that described in the solar nebula theory formed the planets, which of the planets would be expected to have the greatest uncompressed density? |
The one closest to the star. |
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Outgassing is |
the release of gas from rocks as they are heated. |
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The asteroid belt is found between which two planets' orbits? |
Mars and Jupiter |
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The first solid grains of ______ formed in hot regions near the sun. Much farther from the sun the first grains (or rather flakes) of ________also formed by a similar process as the close-in grains, _______. |
iron; water ice; condensation |
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The oldest rocks found on Earth are about ____ years old. |
4.4 billion |
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Which one of the following IS a characteristic of Jovian planets? |
low average density |
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A spectroscopic binary shows periodic variations in its |
radial velocity. |
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Convection is important in stars because it |
mixes the gases of the star and transports energy outward in the star. |
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Star clusters are important to the study the stellar evolution because stars in a given cluster have the same |
age |
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The lower edge of the Main Sequence band is known as ____ and represents the location in the HR-diagram at which stars begin their lives as main sequence stars. |
the zero-age main sequence |
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A planetary nebula is |
the expelled outer envelope of a medium mass star. |
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A Type I supernova is believed to occur when |
a white dwarf exceeds the Chandrasekhar limit. |
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About how long will a 0.5 star spend on the main sequence? |
57 billion years |
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If the theory that novae occur in close binary systems is correct, then novae should |
repeat after some interval. |
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Massive stars cannot generate energy through iron fusion because |
both fusion or fission of iron nuclei absorb energy |
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Stars in a star cluster |
all have the same age and all have the same chemical composition |
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The Crab nebula is |
supernova remnant. |
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The explosion of a supernova typically leaves behind |
a shell of hot, expanding gas with a pulsar at the center. |
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The theory that the collapse of a massive star's iron core produces neutrinos was supported by |
the detection of neutrinos from the supernova of 1987. |
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What nuclear fusion mechanism does an isolated white dwarf use to generate energy? |
White dwarfs don't generate their own energy. |
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Where are elements heavier than iron primarily produced? |
Supernovae |
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____ is a form of electromagnetic radiation produced by rapidly moving electrons spiraling through magnetic fields. |
Synchrotron radiation |
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A group of 10 to 100 stars that formed at the same time but are so widely scattered in space their mutual gravity cannot hold them together is called |
an association. |
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How does the traditional theory of the formation of the galaxy explain the origin of globular clusters? |
They formed early on during the free-fall collapse of the proto-galactic material. |
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The age of the Milky Way galaxy has been estimated to be at least 13 billion years based on |
observations of globular clusters |
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The chemical abundance of population I stars |
indicates that the material they formed from had been enriched with material from supernovae. |
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The orbits of population I stars |
are confined to disk of the galaxy and are nearly circular |
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The period-luminosity relation is useful in determining |
the distance to globular clusters that contain Cepheid variables. |
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Which of the following can't be associated with the spiral arms of a galaxy? |
Metal poor stars |
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Younger stars have more heavy elements because |
the heavy elements were made in previous generations of stars. |
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____ of the Milky Way contains mostly old (population II) stars and globular clusters. |
The spherical halo component |