Elementary Astronomy PHYS 103
Retrograde Motion refers to the
westward motion of the planets relative to the stars.
Which of the following magnitudes corresponds to the brightest star? +3.4. +5.6. +2.1. -1.5. +1.2.
-1.5.
As of 2020, how many space probes had flown past Uranus closely enough to take detailed pictures?
1
A star is observed to have an apparent brightness which is 10⁻⁶ times its absolute brightness. How far away is it?
10,000 parsecs.
A star is found to have absolute magnitude -1 and apparent magnitude 19. How far away is it?
100,000 parsecs.
The number of near-Earth asteroids that are more than one kilometer in diameter appears to be close to
1000
Suppose that you lift an object by exerting an upward force of 22 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total force on the object?
12 Newtons.
What total force will cause an object with a mass of 10kg to gain 5 meters per second every second?
50 Newtons.
The first spacecraft to go into orbit around Saturn was
Cassini-Huygens.
Which of the following types of objects are usually made of ice and possibly frozen gas.?
Comets
In the Hertzsprung-Russelll diagram shown, point number 2 could be a
F0 star of absolute magnitude -5.
Joseph Weber designed a series of devices to detect ripples in spacetime, called gravitational waves. After several years of effort, Joe announced that he had detected gravitational waves. He built several versions of his devices and they all detected the waves. When other people tried to build similar devices, none of them detected anything at all. Joe's evidence was ignored by the scientific community because
Joe's observations were not reproduced.
An example of a planet which may occasionally have liquid water but retains an atmosphere of mostly carbon dioxide is
Mars
Which of these planets is the farthest from the Sun? Mars Mercury Venus Earth
Mars
Which of these Mars rovers operated on the surface of Mars for fifteen years? Opportunity Pathfinder Spirit Curiosity Surveyor
Opportunity
The star Sirius can be located by using the pointer stars in
Orion.
From his observations of the phases of Venus, Galileo concluded that the Ptolemaic model of planetary motion was wrong because it predicted
That there could never be a full Venus, but Galileo saw one
Based on our observations of planetary systems that are forming now, which of these situations is LEAST likely to occur on a planet in a distant binary star system?
You see two suns, both of them looking similar in size to our own Sun, in widely separated parts of the sky.
A star whose full spectral type is B5V is
a bright blue main sequence star.
The time it takes for the Celestial sphere to rotate once relative to the Earth is called
a sidereal day.
We see what appears to be a single star. However, when the light from the star is put through a spectrometer, we see that its spectrum is shifting back and forth. The star is most likely
a single-line spectroscopic binary system.
In a particular binary star system, we are only able to determine a minimum mass for each star and cannot determine the angle between our line of sight and the plane of the stars' orbits. This system is most likely
a spectroscopic binary system.
In the present surface environment of Mars, water has been confirmed to exist
as short-lived spurts of liquid water.
Comets that originate in the Outer Oort Cloud have orbits that are
at all angles to the plane of the solar system.
As Saturn rotates,
both its magnetic poles remain almost motionless at its geographic poles.
Suppose that you drop two objects from the same height at the same time. Both objects are heavy enough to be unaffected by air resistance. If one object is twice as heavy as the other, Galileo predicted that
both objects would hit the ground at the same time.
The Ptolemaic model of the Solar System has each planet moving along a
circular epicycle whose center, in turn, moves around the Earth
Stars usually come in clusters, all born at about the same time, because
collapsing interstellar clouds usually fragment.
When a space probe uses a gravitational slingshot maneuver, it
comes close to a planet to change the probe's speed and direction
Mars' orbit is currently (within the last few hundred years)
elliptical enough to make the intensity of sunlight vary by 40 percent.
The magnetic field of Mars is
essentially zero.
The atmosphere of Pluto is now known to
extend a thousand miles above its surface.
The rotation rate of Saturn
has not been exactly determined because different methods give somewhat different results.
The circular structures on the surface of the Moon are the result of
impacts
The presence of frozen water on Venus is
impossible because every part of it is too hot for water ice.
A model in which the Moon forms from the same rotating cloud of gas and dust as the Earth would predict that the Moon's orbit should be
in the plane of the Earth's equator.
The Law of Inertia says that if an object is not acted on by any outside force,
its acceleration will be zero.
Galileo said that once an object is set in motion, it will keep moving at the same speed so long as
no force is acting on it.
The observed magnetic field of Mercury is surprising because it was expected to have
no magnetic field at all because it rotates so slowly.
The distance from the Earth to the Sun is
one astronomical unit.
The wavelength of the sound waves that correspond to middle-C is about 4 feet. If you are standing 4 feet away from a piano that is playing that note, then between you and the piano there will usually be
one region of maximum pressure.
Pluto has been visited by
one space probe, New Horizons.
For a spectroscopic binary star system, we can determine
only a minimum mass for each star
The Earth's magnetic field plays an essential role in
protecting the Earth from charged particles from the Sun.
A hydrogen atom with its electron removed (a H⁺ ion in other words) is actually a
proton.
By making extensive observations of planetary motion, Tycho Brahe
provided accurate data for the first time.
Which of the following types of radiation has the lowest frequency on this list? red light. infrared light. green light. radio waves. heat radiation.
radio waves.
Shear waves normally propagate
slower than pressure waves.
The Kepler Spacecraft was designed to measure
small changes in starlight from nearby stars.
The stratosphere is where one finds
smoke and dust lingering for years.
The Soviet Union had a secret program to put the first human on the Moon. This program
test launched their Moon Rocket several times, but it blew up each time.
The recoil or 'kick' of a gun that is firing a bullet is a force exerted on the gun by
the bullet.
The wavelength of a wave is defined to be
the distance from one crest to the next.
By measuring the angle between the Sun and the Moon when the Moon was in its first or third quarter, the ancient Greeks were able to calculate
the distance from the Earth to the Sun.
During a meteor shower, shooting stars seem to be coming from
the radiant
In SETI programs, the "water hole" refers to
the range of signal frequencies between emissions caused by hydrogen and hydroxyl molecules.
Einstein's Theory of Relativity has passed every observational test for over 100 years. Among other things, it predicts that no material object can go faster than the speed of light. Fred Zveistein (twice as smart as Einstein) has a new theory that predicts that some material objects can go faster than light. Fred presents his new theory at a scientific meeting (in 2009). These meetings have several talks going on at the same time, so people normally move from one room to another to hear the talks they are interested in. When Fred gets up to talk, everyone leaves the room to go to other talks. The reason for this behavior is that
there is no interest in replacing a theory that has passed every observational test.
Venus retains a dense carbon dioxide atmosphere because
there is no liquid water there.
Mercury rotates so that its sidereal day lasts for:
two thirds of a complete orbit around the Sun.
According to our current model of how magnetic fields arise, the magnetic field of Earth's Moon is
understandable since the Moon rotates slowly and probably has no iron core.
Large numbers of protostars can be seen by using
an infra-red telescope.
Current theory says that the Moon formed when
another planet collided with Earth.
Hydrated minerals on the Moon
are almost completely absent.
Asteroids can be made of
rock and possibly iron.
Barnard's star is a near neighbor of the Sun whose properties we know quite well. It is a type M4V with absolute magnitude 13.22. Suppose that another star of spectral type M4V is observed to have apparent magnitude 8.22. How far away is it?
1 parsec.
The apparent brightness of our Sun is roughly 1000 watts per square meter. At a distance of 30 times the Earth-Sun distance, the apparent brightness of our Sun would be
1.1 watts per square meter.
What total force will cause an object with a mass of 2kg to gain 5 meters per second every second?
10 Newtons.
Suppose that you lift an object by exerting an upward force of 12 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total force on the object?
2 Newtons.
Compared to the Earth, the planet Uranus is roughly
4 times as large.
The Moon Charon orbits a point that is
Not inside Pluto at all.
Once its rockets have ceased firing, an Intercontinental Ballistic Missile will follow a path that is best described as
an ellipse with the center of the Earth at one focus.
Kepler found that the orbit of Mars is best described as
an ellipse.
Saturn has
an extensive ring system made of ice-covered rocks.
The number of near-Earth asteroids is large because they
are kicked out of the asteroid belt by Jupiter's gravity.
According to the current model of the early history of the Solar System, the formation of the Oort Cloud happened
at the same time as the the rain of comets that supplied water to the Earth and other planets.
The objects of the Kuiper belt are mostly orbiting
beyond all of the Jovian planets.
A converging mirror of the sort that is used to collect light in astronomical telescopes
has a focal point on the same side of the mirror as the light source.
The most common element in the universe is
hydrogen.
Comets are usually made of
ice and possibly frozen gas
The photosphere of a protostar
is where light is last scattered.
An artificial satellite such as the International Space Station stays up because
it falls below a straight-line path in exactly the same way that the curved surface of the Earth does.
The Jovian planets typically have
large systems of moons.
As the two foci of an ellipse are moved apart, the shape of the ellipse becomes
more like a line between the foci.
At midsummer in Murmansk (which is the largest city north of the Arctic Circle), the Sun stays above the horizon for several days. This observation would conflict with the predictions of a model of the Sun's motion that has the Sun
moving over and under a flat Earth.
The Opportunity Mars rover
operated on Mars for fourteen years.
Since the last Apollo mission to the Moon and the last Soviet LUNA sample-return mission
spacecraft began to be sent there again by 1994.
The time when the noon sun is highest in the sky is called
the Summer Solstice.
In Kepler's Laws of planetary motion the Earth moves around a Sun that is fixed in space. In Newton's theory,
the Sun and Earth move around a common center of mass.
A hydrogen bond is the result of
the electrical attraction between a hydrogen atom on one molecule and an oppositely charged part of another molecule
A converging lens will send light rays that are parallel to the axis through
the focal point of the lens.
If you are told that an object that weighs 20 Newtons is raised a distance of 10 meters, you know that.
the force of gravity on the object is 20 Newtons.
Stellar Parallax is caused by
the motion of the Earth around the Sun.
The first major failure of the Ptolemaic Theory to predict the results of observations was
the phases of Venus.
You hear about an asteroid impact threat at level 10 on the Torino Scale. You should
think about ways to get off the planet.
Because mirrors only use one surface, they have a big advantage over lenses: They can be
thinner and larger in diameter.
A planet that is following Kepler's Laws, accelerates
toward the Sun.
If an object is moving at constant speed in a straight line, its acceleration is
zero.
The star π³-Orionis is 8 parsecs from our Sun. The light from π³-Orionis has been traveling for
26.4 years.
Tycho Brahe's careful observations of the planets agreed, to within observational error, with
None of these systems.
Which of the following objects has a magnetic field similar in intensity to the Earth's field?
Saturn
Which of the following planets has a system of rings made of ice-covered rocks?
Saturn
You would expect to see a waxing crescent Moon
Setting in the West right after the Sun.
Which of the following statements describes the relation between what we observe and the predictions of the nebular model of the formation of the Solar System?
The model predicts icy planets farthest from the Sun and we observe icy planets there.
An example of a planet with no liquid water at all and a dense carbon dioxide atmosphere is
Venus
Which of the following three systems is regarded as the most normal for a terrestrial planet?
Venus, with no moons at all.
The temperature at the poles of Mercury is expected to be
Very hot all of the time on mountain peaks hit by the Sun and very cold all of the time in craters never hit by the Sun.
Which of the following spacecraft was the second to fly past Saturn and the first to target the moon Titan?
Voyager 1
Which of the following spacecraft is the only one to have flown past Uranus?
Voyager 2
The star Wemadeit shows a stellar parallax angle of 0.2 seconds of arc while the star Waytoofar shows a stellar parallax angle of 0.3 seconds of arc. From this, you can conclude that
Waytoofar is closer to our Sun than Wemadeit.
The star Wemadeit shows a stellar parallax angle of 0.3 seconds of arc while the star Waytoofar shows a stellar parallax angle of 0.4 seconds of arc. From this, you can conclude that
Waytoofar is closer to our Sun than Wemadeit.
The Great Red Spot is
a hurricane on Jupiter.
An encounter between Earth and an iron asteroid fifty meters in diameter would most likely cause
a large explosion on the ground.
The magnetic field of Jupiter indicates that its core must contain large amounts of
a liquid that can conduct electricity.
Spectroscopic Parallax refers to
a method for finding distances to stars.
Aristarchus of Samos is known for a number of things. One of them was
a model in which the Earth rotates on its axis and revolves around the Sun.
An example of a life form that does not get its energy originally from the Sun would be
a tube worm near a black smoker
In comparison to the Copernican Theory, the Ptolemaic Theory made predictions that were of
about the same accuracy.
In comparison to the established, earth-centered theory, the Copernican Theory of planetary motion made predictions that were of
about the same accuracy.
The ozone layer is where one finds
absorption of ultraviolet radiation.
Adaptive optics is used to correct telescopes for
atmospheric turbulence.
The tail of a comet always points
away from the Sun.
The ion tail of a comet
consists of straight streamers.
The discovery that there is water ice on the Moon has motivated many nations to launch Moon missions because it
could make a Moon base possible.
Kuiper Belt objects are usually made of
ice and possibly frozen gas
The Kuiper Belt is thought to have originated when
icy objects condensed out just beyond Neptune.
The rotation axis of Saturn is
inclined at an angle to the perpendicular that is similar to Earth's rotation axis.
In the time of Galileo, telescopes were
known as novelty items but not used for much.
Suppose that a star has a spectrum that includes red, blue, and violet lines spaced in the pattern of the lines from hydrogen but the violet lines are at 444nm and 420nm instead of the usual 434nm and 410nm. From this evidence, you can conclude that the star is
moving away from us.
Here is the Drake Equation. In this equation, N stands for the
number of communication-capable civilizations in our galaxy.
A star with an absolute magnitude of 8.4 and an apparent magnitude of -1.0 would appear in our sky as a star
of dazzling brightness.
A very large number of new asteroids have been discovered since 1990 primarily because
telescopes started using digital imaging instead of film.
Mars retains a carbon dioxide atmosphere because
the pressure is very close to the triple point of water.
The diffraction limit of a telescope refers to the effect of
the wavelength of light.
The Alpha Centauri star system consists of
two stars in close orbit around each other and a third star orbiting farther out.
A comet that is passing close to the Sun will have a tail that is most likely
very long because sunlight is pushing on it.
When you tune your radio to a frequency of 101 Mega Hertz, you are setting it to accept a radio signal that
vibrates with 101 million maximums per second
A planet whose atmospheric pressure is exactly at the triple point of water and whose surface temperature has a range that includes the triple point will have
water as ice or vapor, depending on the temperature
A world with both liquid water on its surface and carbon dioxide in its atmosphere is unstable because
water dissolves carbon dioxide and takes it out of the atmosphere.
Pioneer 11 was an early space probe sent to fly past
Saturn
Which of the following magnitudes corresponds to the dimmest star? +1 +2 +3 0 +4
+4
Which of the following temperatures is closest to what you might expect on the planet Jupiter?
-250F
The number of moons of Mercury is
0
An ion rocket engine produces 1 Newton of thrust. What acceleration can it give to a space probe with a mass of 1000kg?
0.001 m/s².
The Law of Inertia states that a moving object will
keep moving if no force acts on it.
A solar sail is a large sheet of light-reflecting plastic spread on an extremely low-mass framework and attached to a spacecraft. Sunlight exerts a force on the sail and moves the spacecraft. Suppose the spacecraft has a total mass of 100kg (including the sail) and sunlight exerts a total force of 2N on the sail. What will be the acceleration of the spacecraft?
0.02m/s².
A star is seen to move by 0.2 seconds of arc between February 1, 1999 and August 1, 1999 and then back to its starting point on February 1, 2000. What is the parallax angle for this star?
0.1 seconds of arc.
A star is seen to move by 0.8 seconds of arc between March 1, 1999 and September 1, 1999 and then back to its starting point on March 1, 2000. What is the parallax angle for this star?
0.4 seconds of arc.
As of 2020, how many space probes have flown past Neptune closely enough to take detailed pictures?
1
How many of the moons of Saturn are larger than the Earth's Moon?
1
In the Earth's atmosphere, the percentage that is water vapor is roughly
1%
The star Tau Ceti has moved across the sky by 1922 seconds of arc during the last thousand years, more than a half of a degree of arc. Its proper motion is closest to
1.9265′′/yr.
The velocity of sound waves is roughly the same for all wavelengths. Suppose that a sound wave has a wavelength of one meter and a frequency of 500Hz. The wavelength of a 1000Hz sound wave would then be
1/2 m.
Cruising far from the Sun, we notice that the Sun's apparent brightness has dimmed to 10 watts per square meter. We know that the apparent brightness at a distance of 1au is 1000 watts per square meter. How far from the Sun are we?
10 au
The asteroids that we really need to know about are the ones that are heading for Earth and are large enough to threaten our species with extinction. Those asteroids are ones larger than
1000
A star is observed to have an apparent brightness which is 10⁻⁴ times its absolute brightness. How far away is it?
1000 parsecs.
Suppose that the color and behavior of a star identify it as a type that we know has absolute magnitude --3. If the star's apparent magnitude is found to be 7, how far away is it?
1000 parsecs.
The density of water is 1000kg/m³, the density of rock is about 3000kg/m³, and the density of iron is 7800kg/m³. Which of the following densities would indicate an object that consists mostly of substances much less dense than rock or iron?
1000kg/m³
Barnard's star shows a proper motion of 10.36 arc seconds per year. In 100 years, its position in the sky changes by
1036 seconds of arc.
The star 61-Cygni is 3.3 parsecs from our Sun. The light from this star in the "serpent holder" constellation has been traveling for approximately
11 years.
At 8pm, you see that the pointer stars of the Big dipper and the star Polaris are arranged in a vertical line. at what time. give or take a minute or so, would you see them arranged at 45 degrees to the vertical?
11:00 p.m. the same day.
Suppose that a flash of lightning from a cloud 5000 meters away is followed by a clap of thunder four seconds later. Assume that the light arrived in a negligible time and calculate the speed of the sound waves.
1250m/s
Uranus rotates on its axis once in about
17 hours
The number of moons of Mars is
2
In the Earth's atmosphere, the percentage that is Oxygen is roughly
20%.
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Earth is number
3
The star epsilon-Eridani shows a heliocentric stellar parallax near 1/3 seconds of arc. The distance from our Sun to epsilon-Eridani is near
3 parsecs.
Compared to the frequency of photons absorbed during a transition from a -5ev state to a -4ev state, transitions from the -5ev state to a -2ev state would correspond to absorbing photons whose frequency is
3 times as high.
The velocity of sound waves is roughly the same for all wavelengths. Suppose that a sound wave has a wavelength of one meter and a frequency of 1000Hz. The wavelength of a 250Hz sound wave would then be
4 m.
The star Kruger 60 shows a heliocentric stellar parallax of almost exactly 0.25 seconds of arc. The distance from our Sun to Kruger 60 is
4 parsecs.
Our own Sun has an absolute visual magnitude of 4.8. A starship that travels 10 parsecs from our Sun and looks back at the Sun will see it as having apparent visual magnitude
4.8.
The Earth's distance from the Sun is defined to be 1 astronomical unit. Neptune is about 30 astronomical units from the Sun. An object in the Outer Oort Cloud might be at a distance from the Sun of
40,000 astronomical units.
The violet lines in the Hydrogen spectrum are normally seen with wavelengths 410 nm and 434 nm. In the light of a star that is moving toward us, we might expect to see those lines at wavelengths of
400 nm and 424 nm
The density of water is 1000kg/m³ while the density of iron is 7800kg/m³. Which of the following values is a plausible value for the density of a terrestrial planet?
5000kg/m³
At 8pm, you see that the pointer stars of the Big dipper and the star Polaris are arranged in a vertical line. How long, give or take a few minutes, would you need to wait to see them arranged in a horizontal line?
6 hours
A star whose apparent brightness is 1/100 that of a first magnitude star would have magnitude
6.
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Uranus is number
7
The density of water is 1000kg/m³ while the density of rock is 3000kg/m³. Which of the following values is a plausible value for the density of a Jovian planet?
700kg/m³
The radiant of a meteor shower is the point in the sky that the
Earth is moving towards during the shower.
The inclination angle of a planet's rotation axis is defined so that a planet that is rotating in the usual direction about an axis that is perpendicular to the plane of the solar system would have an inclination of 0°, while a planet that is rotating in the opposite (retrograde) direction about an axis that is perpendicular to the plane of the solar system would have an inclination angle of 180°. The inclination angle of the planet Uranus is closest to
98°
Which of the following computer programs is the most likely to be considered a scientific model:
A simulation,using currently accepted physical laws, of waves crashing on the beach.
Which of the following objects is the most likely to be considered a scientific model? A blackboard. An accurate map of Richmond. An oil painting of a person. A test-tube. A computer program.
An accurate map of Richmond.
Underneath the Atlantic Ocean is an undersea mountain range called the MidAtlantic Ridge. That ridge is caused by
An upward current in the Earth's Mantel.
Which of these is a statement of the Fermi Paradox? We are never special. Any long-lasting technological civilization should be obvious and might even be visiting us, so where are they? The strength of an interstellar signal falls off as the square of the distance but the expected number of such signals increases as the square of the distance, so where are they? Because time in a moving reference frame is much slower than in the rest frame, aliens can get anywhere they want to in a very short amount of their own time, so where are they? Not only do you never get more than you pay for, you never break even.
Any long-lasting technological civilization should be obvious and might even be visiting us, so where are they?
The first human landing on the Moon was
Apollo 11 in 1969.
The first generally accepted example of Sea-floor spreading was under the
Atlantic Ocean.
Which of the following pictures is the most like the main sequence on a Hertzsprung-Russelll Diagram?
B
You read in an Astronomy book that our Milky Way Galaxy consists of about 200 billion stars. How do you suppose this number was determined?
By using a model of the galaxy that correctly accounts for everything that has been measured so far.
The Galilean satellites of Jupiter are
Callisto, Europa, Ganymede, and Io.
Which of the following substances is the smallest fraction of our atmosphere?
Carbon Dioxide
Which of these Mars rovers has been operating on the surface of Mars for eight years so far (as of 2020). Curiosity Pathfinder Spirit Opportunity Surveyor
Curiosity
In the 1990s astronomical telescopes began to switch from recording images on film to recording them digitally using Charge Coupled Devices. This led to the discovery of new asteroids at a rapid rate because
Digital images could be processed by computers
Of all the things that might go wrong with distances found by using the method that astronmers refer to as the "distance ladder," which of these is the one that an astronomer would say is most likely?
Distant objects are not behaving the same as nearby objects.
In the Hertzsprung-Russell Diagram shown, which point represents a star of type K with absolute magnitude +10?
E
Which of the following spectral classes corresponds to the second lowest surface temperature (on this list)? A B F G K
G
Which of the following spectral types corresponds to the star with the lowest surface temperature?
G5
The first spacecraft to go into orbit around Jupiter was
Galileo.
Which of the following objects is the largest moon of Jupiter?
Ganymede
Which of the following statements is an observation of the natural world?
I saw a full Moon last night.
Which of the following statements is the most likely to be a reproducible observation?
I saw the Sun set at 4:55pm on December 22 in Richmond VA.
The International Space Station (ISS) is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose that it is desired to raise it to a new circular orbit, farther from the surface by having a rocket give it one or more short boosts. Which of the following schemes will work?
Increase its speed to 6 miles per second and then give it another speed boost when its distance from the Earth stops increasing.
The Ptolemaic System continued to be accepted long after such people as Aristarchus and Copernicus had proposed alternatives. All of the following reasons why it lasted so long are at least partly true. Which reason is the one that would be stressed by the philosophy of science that we have been discussing?
It correctly predicted what was observed and thus did not need to be replaced.
The Apollo program was thought to be part of a "race to the Moon" with the Soviet Union. Actually
It was a close race. The Soviets actually built a Moon rocket and tested it.
It is currently thought that moons typically form near
Jovian planets such as Jupiter and Saturn.
In the Hertzsprung-Russelll diagram shown, point number 5 could be a
K2 star of absolute magnitude 10.
The statement that the orbit of each planet is an ellipse with the Sun at one focus is due to
Kepler.
Which of the following types of object could reasonably be described as "dirty snowballs" or, for the larger ones, "flying icebergs?"
Kuiper Belt Objects.
Short-period comets are thought to be
Kuiper belt objects deflected by Neptune.
Which of the following spectral types would you expect to look red in color?
M
The Asteroid Belt is between the orbits of
Mars and Jupiter.
Mars is farther from the Sun than Earth. Which of the following statements is true?
Mars takes longer to go around the Sun than Earth and moves more slowly than the Earth does.
Mercury is closer to the Sun than Earth. Which of the following statements is true?
Mercury takes less time to go around the Sun and moves faster than the Earth.
The angle between the rotation axis of a planet and the perpendicular to the plane of its orbit is called its "axial tilt." Which of these planets has an axial tilt that is less than one degree?
Mercury.
Changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis cause
Milankovich cycles
In a solar day, the sun comes back to the same place in the sky but, in relation to the distant stars, the Earth actually rotates
More than one revolution.
Which of these planets has a rotation axis that is inclined in much the same way as that of Earth?
Neptune
You see a telescope with a long tube and the eyepiece sticking out the side near the top. This telescope uses the
Newtonian Focus.
As seen from far above the Earth's South Pole, the Earth orbits the Sun clockwise and
No planet orbits the Sun counterclockwise.
You are looking down on the Earth from a spacecraft hovering far above. After watching for a while, you notice that, from your perspective, it is rotating counterclockwise. The part of the Earth that is directly below you must be the Earth's
North Pole.
Sarah reports that she saw a green star close to the star Betelguese. She really saw it and was quite surprised. The most likely outcome of her report is that:
Other people look near Betelgeuse. They see the star and confirm her report. She becomes famous as the discoverer of the first green star.
Which of the following statements is falsifiable? Passenger pigeons are extinct. Passenger pigeons are not extinct. Passenger pigeons taste good. Passenger pigeons taste terrible. Passenger pigeons were pests.
Passenger pigeons are extinct.
The first space probe to test the air-bag landing system was
Pathfinder.
Which of the following spacecraft were the first to fly past Jupiter?
Pioneer 10 and Pioneer 11
Which of these was the Solar System model that assumed the Earth is almost fixed and the Sun, Moon, and planets all move on epicycles that, in turn move on circular orbits around the Earth?
Ptolemaic model.
You are having central air conditioning installed in your two-story house and you have a choice between putting the vents on the second floor and putting them on the first floor. Of course, it would be best to put them in both places but you can't do that. Which of the options that you have is best?
Put the vents on the second floor so that the cooled air will descend to the first floor.
The first space probes to land on another planet were from the
Russian Venera series.
The first telescope was (possibly) built by
Someone in the Netherlands.
The first successful soft landing on the Moon was
Surveyor 1 in 1966.
The path of the Sun on the Celestial Sphere is called
The Ecliptic.
Which of Kepler's Laws governs how a particular planet speeds up and slows down?
The Equal Area Law.
Which of the following statements is falsifiable? There is intelligent life on other stars. The Moon is made entirely of cheese. Isaac Newton was the greatest scientist. There is beauty in a sunset. There is cheese on the Moon.
The Moon is made entirely of cheese.
Compare the magnitude of the acceleration of Earth's Moon to the acceleration of falling objects on the surface of the Earth.
The Moon's acceleration is smaller.
Why couldn't we just fly a Space Shuttle to the Moon for at least a fly-by?
The Space Shuttle did not have enough fuel to reach escape velocity
An astronomical unit is defined to be
the average distance from the Earth to the Sun.
Why don't we just shoot all of our really nasty waste products into the Sun where they could not possibly bother anyone?
The Sun is actually the hardest part of the Solar System to get to from here.
The capture theory, in which our Moon forms separately and is captured by the Earth, became popular when computer models showed that such a capture would have been possible.
The capture theory was dropped because it predicts that the Moon should have hydrated rocks and it does not.
Which layer of the Earth has a thickness of only about ten miles?
The crust.
An early measurement of noon Sun angles at the summer solstice at Alexandria and Syene needed one additional piece of information in order to determine the size of the Earth.
The distance between Alexandria and Syene.
A horse is pulling a cart along a road. Which of the following pairs of forces is an action-reaction pair?
The force of horse on the road and the force of the road on the horse
A book, weighing 10 Newtons, sits on a table. Which of the following pairs of forces is an action-reaction pair?
The force that the book exerts on the table and the force that the table exerts on the book.
You are standing in an elevator that is accelerating upward at 1m/s². Which of the following pairs of forces is an action-reaction pair that have to be exactly equal and opposite to each other?
The force that the floor of the elevator exerts on you and the force that you exert on the floor of the elevator.
The frequency of a wave is defined to be
The number of crests that pass in one second.
The motion of the Moon around the Earth causes
The phases of the Moon.
Which of the following circumstances would suggest that a rotating planet contains a core of liquid iron?
The planet is much denser than rock and has a magnetic field.
Einstein's Theory of Gravity has passed every well-understood observational test for over 100 years. However there are some anomalous observations which are not well-understood. For example, the Pioneer space probe is showing tiny deviations from its predicted course as it leaves the neighborhood of our solar system. A new theory, called "Modified Newtonian Dynamics," actually does not do as well as Einstein's Theory at predicting most things, but it does predict those tiny deviations and also accounts for several other, apparently unrelated, anomalous observations as well. From what we have said about the way scientists think, which of the following receptions would you expect this new theory to get?
There is great disinterest because there is no need to replace a theory that has passed every well-understood observational test.
It has been said that the "facts" of science are actually "revisable facts." When do these "revisable facts" get revised?
They conflict with reproducible observations.
One model for the formation of the Solar System is that the planets formed from a cloud of material extracted from the Sun by a chance encounter with a passing star.
This model incorrectly predicts planets orbiting out of the plane of the Sun's equator.
Which of the following objects is the largest moon of Neptune?
Triton.
Which of the following astronomers is regarded as an early example of government-supported Big Science.
Tycho Brahe.
The axial tilt of Pluto is most similar to that of
Uranus
An atmosphere with about 90 times the surface pressure of Earth's is found on the surface of.
Venus
The Cassini-Huygens spacecraft
Went into orbit around the planet Saturn.
Call the time it takes Venus to orbit the Sun a "Venusian year." Call the time it takes Venus to rotate once on its axis relative to the distant stars a "Venusian sidereal day." Which of the following statements about these two time periods is true?
a Venusian year is shorter than a Venusian sidereal day
An area of the sky that is marked by a recognizable pattern of stars is called
a constellation.
A descending convection current in the Earth's mantle is expected to cause
a deep ocean trench where tectonic plates are pulled together.
We see what appears to be a single star. However, when the light from the star is put through a spectrometer, we see two distinct spectra, shifting back and forth. The star is actually
a double-line spectroscopic binary system.
The Inner Oort Cloud is
a doughnut-shaped region with objects above and below the plane of the solar system.
A sidereal day is
a few minutes shorter than a solar day.
Jupiter has
a few rings made of dark rocks.
The ancient Greeks had difficulty accounting for the motion of a thrown object because they thought that
a force was needed to keep the object moving.
The ancient greeks thought that
a heavy object should fall faster than a lighter object because the heavy object is pulled down with more force.
In a particular binary star system, we are able to determine the masses of both stars in the system as well as the angle between our line of sight and the plane of the stars' orbits but cannot determine the diameters or atmospheric compositions of the two stars. This system is most likely
a visual binary system.
The atmospheric pressure on the surface of Mars is
about 1% the surface pressure of Earth's atmosphere.
The largest moon of Pluto has
about 1/2 the diameter of Pluto.
The magnetic field of Jupiter is
about 10 times the intensity of the Earth's magnetic field.
So far (as of 2020), the planet Venus has been visited by
about 38 successful space probes.
Since 1990, the major spacefaring nations, Europe, China, Russia, Japan, India, and the U.S., have begun to return to the Moon. As of 2020, of these six space programs,
all except Russia have sent probes or orbiters to the Moon.
In addition to being accurate, Tycho Brahe's observations focused on measuring the positions of the planets
all the time.
Saturn's magnetic North and South poles are
almost exactly aligned with its rotation axis.
A time of 24 hours is
almost exactly equal to a solar day (within a second).
The rotation axis of Uranus is
almost in the plane of its orbit so that its ring system can sometimes be seen as near-circles.
Jupiter has almost no atmosphere. an atmosphere of carbon dioxide with about 90 times the surface pressure of Earth's. an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's. an atmosphere of Hydrogen and Helium with no real surface. an atmosphere of Hydrogen and Helium with some methane.
an atmosphere of Hydrogen and Helium with no real surface.
Saturn has almost no atmosphere. an atmosphere of carbon dioxide with about 90 times the surface pressure of Earth's. an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's. an atmosphere of Hydrogen and Helium with no real surface. an atmosphere of Hydrogen and Helium with some methane.
an atmosphere of Hydrogen and Helium with no real surface.
Neptune has almost no atmosphere. an atmosphere of carbon dioxide with about 90 times the surface pressure of Earth's. an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's. an atmosphere of Hydrogen and Helium with no real surface. an atmosphere of Hydrogen and Helium with some methane.
an atmosphere of Hydrogen and Helium with some methane.
Mars has an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's. almost no atmosphere. an atmosphere of carbon dioxide with about 90 times the surface pressure of Earth's. an atmosphere whose temperature and pressure permit all three forms of water. an atmosphere whose temperature and pressure permit all three forms of methane.
an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's.
Titan has
an atmosphere whose temperature and pressure permit liquid methane.
In a particular binary star system, we are able to determine the masses and diameters of both stars This system is most likely
an eclipsing spectroscopic binary system.
Kepler's First Law of Planetary Motion is that the orbit of each planet is
an ellipse with the Sun at one focus.
Pluto has
an extensive atmosphere of nitrogen and methane.
The luminosity class of a star is
an indication of the broadening of its spectral lines
The main reason that telescope mirrors can be much larger than lenses is that the mirrors
are lighter because they are thinner.
Had Jupiter ignited, we would be living in a multiple star system. Such systems
are quite common.
Our Sun sends out intense streams of charged particle radiation. Most of these charged particles
are trapped by the Earth's magnetic field for a while and then strike the atmosphere over the poles.
Asteroids are usually found in the asteroid belt, which is
between the orbits of Mars and Jupiter.
The Kuiper Belt is mostly located
beyond the orbit of Neptune.
A large asteroid impact can affect the Earth's climate primarily by
blocking the sunlight with its smoke and dust.
From the timing of lunar eclipses, the Ancient Greeks were able to
calculate the distance from the Earth to the Moon.
The problem of stars "twinkling" due to atmospheric turbulence
can be corrected by using a guide star.
Several gases can absorb and re-radiate infra-red light. The one that is thought to be most affected by human activities is
carbon dioxide.
The key advantage of Carbon over Silicon as the basic element for life is that
carbon forms more stable compounds than silicon
The hydrogen atoms in a water molecule
carry positive electrical charges.
At present (within the last few hundred years), the distance from Mars to the Sun
changes enough to make the intensity of sunlight vary by 40 percent.
Milankovich cycles refer to
changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis.
According to our current (very tentative) estimates, a spaceship travelling from our Sun to one of the nearest stars such as Alpha Centauri A probably
could make the trip in many short hops between rogue planets along the way.
The impacts of large objects on the surface of the Moon have caused
craters.
Apollo 8 made the first
crewed orbit of the Moon.
Copernicus said that the rotation of the Earth on its axis caused the
daily motions in the heavens.
For stars on the main-sequence, stars with decreasing mass have
decreasing surface temperature and absolute brightness.
Far from the Sun, a comet is basically a
dirty lump of frozen gas and ice.
Neptune's magnetic North and South poles are
displaced from its rotation axis poles and also from the center of the planet.
Uranus' magnetic North and South poles are
displaced from its rotation axis poles and also from the center of the planet.
Uranus's magnetic North and South poles are
displaced from its rotation axis poles and also from the center of the planet.
Liquid water tends to remove carbon dioxide from the atmosphere of a planet by
dissolving it and washing it out of the atmosphere.
Copernicus said that the daily motions in the heavens were caused by the
earth turning on its axis.
Information about the structure of the Earth's interior comes mainly from
earthquake waves.
As Saturn orbits the Sun, we see its rings from different angles. We see the rings
edge-on as a straight line exactly twice each orbit.
Which of the following particles has the smallest mass?
electron
Which of the following particles would be electrically attracted by a positron?
electron.
According to current theories it seems likely that "rogue planets" or planetary mass objects that are not in orbit around any particular star
exist and may be more common than planets in orbit around stars.
The Oort Cloud is located
far beyond the orbit of Pluto.
Carbon is essential for all life we know about because it
forms complex compounds.
When a large interstellar cloud collapses, it usually
fragments into several smaller clouds which then form stars.
Sedna is thought to be
from the Inner Oort Cloud.
According to our current (very tentative) estimates, a spaceship travelling from our Sun to one of the nearest stars such as Alpha Centauri A would probably be traveling through the Oort cloud of our Sun and that of Alpha Centauri A for a distance that is
half of the whole trip.
Mercury rotates so that it
has a solar day that last for two complete orbits around the Sun.
The Curiosity Mars rover
has been operating on Mars for eight years so far (as of 2020.
The side of the Moon that faces away from the Earth
has only a few small lunar maria.
Suppose that an object with a mass of one kilogram and an object with a mass of two kilograms are both in free fall near the Earth's surface. As compared to the one kilogram object, the two kilogram object accelerates
he same because gravity pulls on it more strongly and it has more inertia
Which of the following types of radiation has the second lowest frequency on this list? red light. infrared light. green light. radio waves. heat radiation.
heat radiation.
The troposphere is where one finds
hurricanes.
The statement that lunar material is much "dryer" than Earth material refers to the absence of
hydrated minerals
The portion of the Earth that is solid iron and nickel is the
inner core.
An asteroid impact that leaves a huge crater is probably due to an asteroid that is made of
iron and nickel.
If the frequency of electromagnetic radiation goes from 6×10¹⁴Hz, to 2×10¹⁴Hz, the energy of each individual photon in the radiation
is divided by 3.
The Moon's orbit around the Earth
is elliptical enough to give us an annular solar eclipse when the Moon is near its apogee.
If the acceleration of an object is zero, its speed
is not changing.
According to Newton's Law of Gravity, the gravitational attraction of the Earth for other objects, such as the Moon, apples on trees and spacecraft in low earth orbit,
is smaller for objects farther from the Earth but never vanishes entirely
The gravitational attraction of the Earth for other objects,
is smaller for objects farther from the Earth but never vanishes entirely.
Pluto is always closer to the Sun than Uranus. is sometimes closer to the Sun than Neptune and sometimes farther from the Sun. is always farther from the Sun than Neptune. is sometimes closer to the Sun than Uranus and sometimes farther from the Sun is always closer to the Sun than Neptune.
is sometimes closer to the Sun than Neptune and sometimes farther from the Sun.
One reason that the Copernican System failed to fit Tycho's observations was that
it used circular orbits instead of ellipses.
In the original Solar Nebula, objects that condensed near the protoSun tended to be mostly rock and iron rather than volatile gases and water because, in that part of the nebula
it was too hot for volatile gases and water to condense.
Aristarchus measured the angle between the Sun and the Moon when exactly half of the Moon was illuminated. If the Sun were actually just two or three times as far away as the Moon, he would have found that angle to be
less than 90 degrees by an amount that was easy for him to measure.
Compared to the rest of the Lunar surface, the Lunar Maria are
lower and younger
Ultraviolet light is sometimes described as either UV-A or UV-B. The UV-A variety is supposed to be less damaging to your skin. You can conclude that of the two types, the UV-A variety has the
lower frequency.
The layer of the Earth's interior that flows like a liquid under gradual pressure but acts like a stiff solid under sudden pressure changes is the
mantle.
The debris of long-dead comets causes
meteor showers.
When detailed tracking of asteroid 2008 TC₃ showed that it would hit the Earth, the asteroid officially became a
meteoroid.
The blue color of the planet Uranus is caused by the presence in its atmosphere of
methane.
The epicenters of earthquakes are located
mostly along the edges of moving plates.
The gravitational influence of the planets causes asteroids to
move from the asteroid belt into the inner solar system.
In one day, the position of the Sun on the Celestial Sphere
moves eastward along the ecliptic by 1°.
Suppose that a star has a spectrum that includes red, blue, and violet lines spaced in the pattern of the lines from hydrogen but the red line is has a wavelength of 650 nm instead of the usual 656 nm. From this evidence, you can conclude that the star is
moving toward us.
The temperature on Saturn is
much colder than anywhere on Earth.
Heliocentric Stellar Parallax causes
nearby stars to shift back and forth once a year.
As seen from North America, the constellation Casseopeia
never sets
A converging lens will send all of the light that it receives from a distant star through a point
on the side of the lens opposite the star.
The Moon rotates on its axis relative to the distant stars
once every sidereal month
Suppose that an asteroid, about 1 kilometer in diameter, shows a 1 in 100 probability of an Earth impact fifty years in the future. Assume that an impact will trigger climate changes that would kill one billion (1,000,000,000) people. Also assume that each of these deaths represents $100,000 in lost production. Using the cold economic logic that we discussed in class, how much money should be budgeted to deflect the asteroid?
one trillion dollars ($1,000,000,000,000).
The daily rising and setting of the Sun happens
only south of the arctic circle and north of the antarctic circle.
The part of a protostar where the density first becomes low enough for light to escape is called the
photosphere.
The habitable zone of a planetary system is defined to be the region where
planetary surfaces permit the existence of liquid water.
On Earth, a stable long-term carbon cycle could not exist without
plate tectonics recycling the sea floor into the Earth' interior.
The presence of frozen water on Mercury is
possible because it has almost no axial tilt so that its poles never directly face the Sun.
When a seismometer detects an earthquake, the first signal to arrive is usually the
pressure wave.
A star that is cooler than most other stars will probably look
red.
Space probes often visit several planets before getting to their final destinations. The main reason they do this is to
reduce the amount of rocket fuel needed.
To see small but bright objects such as the ice caps on Mars, you would need a telescope with large
resolving power.
Planets that are in orbit around stars other than our own Sun are more often found by observing
small wobbles in their primary stars.
Venus rotates backwards so that the Sun rises in the West. always keeps the same side toward the Sun so that solar time never changes. has a solar day that lasts for two complete orbits around the Sun. has a solar day that lasts for three complete orbits around the Sun. has a solar day that is very close to an Earth day in length.
rotates backwards so that the Sun rises in the West.
The magnetic field of Saturn is
similar in intensity to the Earth's magnetic field.
If an asteroid that is 50 meters in diameter strikes the Earth, the result is likely to be
similar to a nuclear explosion.
A full cycle of day and night on Mars is called a `sol.' In terms of 24 hour Earth days, a Martian sol is
slightly longer than one Earth day.
Earthquakes are often caused by
slipping tectonic plates.
A rocket is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose that it is desired to lower it to a new circular orbit, sliightly closer to the surface. The rocket flips over and fires its main rocket engine in a short burst to slow its speed to 4.96 miles per second. What must it do next?
slow its speed again by a bit when its distance from the Earth stops decreasing
Jupiter has the most mass of any planet in our Solar System and is also the largest planet. Objects that have still more mass than Jupiter and are not stars are usually
smaller than Jupiter.
For the ancient Greeks, the most basic of several clues that the Sun is farther from the Earth than the Moon came from
solar eclipses.
When Galileo dropped a wooden ball and a heavier iron ball at the same time, he found that
sometimes the wooden ball hit first, sometimes the iron one hit first.
Aristotle said that the amount of force on a moving earthly object determines its
speed.
The chlorophyll in plants uses sunlight to
split water into hydrogen and oxygen
Consider a light source whose absolute magnitude can be deduced from the properties of the light that reaches us from that source. Astronomers often refer to this sort of object as a
standard candle.
Think of the `front' of a telescope as the end that light enters. A telescope with Newtonian Focus has the eyepiece
sticking out the side near the front.
Which of these is a distinctive feature of the Earth's atmosphere? temperature and pressure permit all three forms of water. the presence of nitrogen. the presence of water vapor. the presence of carbon dioxide. temperature and pressure permit all three forms of methane.
temperature and pressure permit all three forms of water.
The stars, as seen from the Earth, appear to be attached to
the Celestial Sphere, a sphere that surrounds the Earth.
An annual meteor shower occurs when
the Earth passes through comet debris.
Icy objects condensed from the outskirts of the Solar Nebula to form
the Kuiper belt.
The term 'greenhouse effect' refers to
the absorption of infrared light by gases in the atmosphere.
The Kuiper Belt was named after Gerard Kuiper, who said that
the belt formed early in the history of the solar system but should not still be there because Pluto would have cleared its neighborhood of smaller objects.
According to Galileo, a thrown spear keeps moving after it has left the spear thrower's hand because
the force of friction with the air is not enough to stop the spear.
If you are told that a 20 kilogram object is raised by 10 meters, you know that
the mass of the object is 20 kilograms.
One way to change the course of an asteroid is to place a `mass driver' on it. The mass driver is really just a catapult that throws things (like rocks for example) away from the asteroid. The force that acts on the combined object (mass driver plus asteroid) is actually exerted by
the rocks that the catapult throws.
The Moon rotates on its axis so that it always keeps
the same side (its far side) pointed away from the Earth.
Moon missions since 2007 have mostly been focused on
the search for water needed for a Moon base.
The main difficulty with multiple star systems such as Alpha Centauri as places to look for life is that
the shifting gravitational fields of the orbiting stars might mean that there are no stable orbits in their habitable zones.
The ancient Greeks argued that the Earth cannot be moving because such a motion would cause apparent shifts in the positions of stars. This argument was wrong because
the stars are so far away that the shifts due to the Earth's motion are extremely small.
A normal Helium nucleus consists of two protons and two neutrons. The protons actually repel each other because they have the same charge. The main force that holds this nucleus together is
the strong force.
One reason that temperatures are higher in the summer than in the winter is that
the sun is higher in the sky in the summer.
One reason that temperatures are lower in the winter than in the summer is that
the sun is lower in the sky in the winter.
The main reason that the SETI@home system needs to use the computing power of 5.2 million participating home computers is that
they are collecting and analyzing signals from millions of different radio channels.
The magnetic field of Jupiter is
tilted relative to the planet's rotation axis but not offset from its center.
In a Hertzsprung-Russell diagram, the surface temperature of stars increases going
to the left.
When Newton calculated the magnitude and direction of the acceleration for a planet that was following Kepler's Laws, he found that the direction of the acceleration was
toward the Sun.
The lower left of a Hertzsprung-Russell diagram is where one finds
white dwarf stars.
If we wish to find life with a carbon-return process similar to the one here on Earth, we should look for planets
with thin, unstable surfaces.
In a region of the atmosphere in which the temperature rises with increasing altitude
you expect no changes.
In a region of the atmosphere in which the temperature falls with increasing altitude
you expect rapid changes.