Astronomy Final Exam
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
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.
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.
In our Milky Way Galaxy, the Orion Spur is the
closest arm to our Sun.
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.
Meteor showers are caused by
comet debris.
The ion tail of a comet
consists of straight streamers.
The strongest evidence that Earth life is all descended from a single self-copying molecule is that all Earth life
contains the same version of molecules that have different mirror-image forms.
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.
An advantage of carbon dioxide as the starting form of carbon for use by living things is that it
dissolves in liquid water.
Liquid water tends to remove carbon dioxide from the atmosphere of a planet by
dissolving it and washing it out of the atmosphere.
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 -1ev state would correspond to absorbing photons whose frequency is
4 times as high.
Compared to the Earth, the planet Uranus is roughly
4 times as large.
A nearby cluster of several thousand galaxies is called
The Virgo Cluster.
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.
In the present surface environment of Mars, water has been confirmed to exist
as short-lived spurts of liquid water.
Which of the following astronomers is regarded as an early example of government-supported Big Science.
Tycho Brahe.
Hydrated minerals on the Moon
are almost completely absent.
The number of near-Earth asteroids is large because they
are kicked out of the asteroid belt by jupiters gravity
An average star that is farther out from the galactic center than our sun would most likely be moving
at about the same speed as our sun.
The magnetic field of Jupiter indicates that its core must contain large amounts of
a liquid that can conduct electricity.
Comets that originate in the Outer Oort Cloud have orbits that are
at all angles to the plane of the solar system.
The Oort cloud of our Sun reaches
at least a quarter of the way to the nearest star.
The source that is called Sgr A* emitsboth X-rays and radio waves.
both X-rays and radio waves.
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.
As of 2018, the search for near-Earth asteroids that could threaten global effects has most likely
found more than 90% of them.
A spectrum is defined to be the set of
frequencies or colors present in a light source.
Sedna is thought to be
from the Inner Oort Cloud.
The troposphere is where one finds
hurricanes.
Observations of the collision of two galaxy clusters have shown that dark natter
is not the result of an incorrect theory of gravity.
When ice melts, the resulting liquid water occupies
less volume than the ice did.
The surface of Jupiter is marked by
light and dark bands circulating in opposite directions.
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 original source of energy for life forms that live near a black smoker is
often chemicals generated by the heat of the Earth's interior.
Asteroids a few meters in diameter hit the Earth's atmosphere
once every few years and cause air bursts similar to small nuclear weapons.
Oxygen is
one of the four most common elements in the universe.
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.
Most plants here on Earth are green because the process of converting carbon dioxide and water into organic matter uses only
red, blue, and violet light.
The time when the noon sun is highest in the sky is called
the Summer Solstice.
The term 'greenhouse effect' refers to
the absorption of infrared light by gases in the atmosphere.
In SETI programs, the "water hole" refers to
the range of signal frequencies between emissions caused by hydrogen and hydroxyl molecules.
The spacecraft Galileo
went into orbit around the planet Jupiter and dropped a probe into its atmosphere.
Retrograde Motion refers to the
westward motion of the planets relative to the 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 falls with increasing altitude
you expect rapid changes.
If an object is moving at constant speed in a straight line, its acceleration is
zero.
You may hear about an Earth Impact Warning at a certain level on the Torino Scale. That scale ranges from zero to
10
Which of the following temperatures is closest to what you might expect on the planet Jupiter?
-250F
The number of moons of Uranus that are larger than Earth's Moon is
0
The number of objects that have been observed to be orbiting in the Outer Oort Cloud is approximately
0
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.
The closest star to our sun is about four light years away. In the center of our galaxy, a typical distance between neighboring stars would be
0.04 light years.
In the Earth's atmosphere, the percentage that is Carbon Dioxide is roughly
0.04%.
As of 2018, how many space probes had flown past Uranus closely enough to take detailed pictures?
1
As of 2018, 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%.
As of 2018, how many space probes have flown past Neptune closely enough to take detailed pictures?
1.
The largest moon of pluto (Charon) has
1/2 the diameter of Pluto
What total force will cause an object with a mass of 2kg to gain 5 meters per second every second?
10 Newtons.
Saturn rotates on its axis once in about
10 hours.
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 meters.
An asteroid whose impact generates a planet-wide catastrophe, changing the climate everywhere, probably has a diameter of about
1000 to 10,000 meters.
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.
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 is closest to the average density of Jupiter?
1200kg/m³
Assume that the Hubble constant is 72 km/s/Mpc. If a galaxy is 20Mpc away, how fast is it moving away from us?
1440km/s
As of July, 2018, The number of confirmed exoplanets found by the transit photometry method is closest to
2500.
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 Inner Oort Cloud might be at a distance from the Sun of
15,000 au
Uranus rotates on its axis once in about
17 hours.
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
2 times as high.
In the Earth's atmosphere, the percentage that is Oxygen is roughly
20%.
As of July, 2018, The number of confirmed exoplanets found by the transit photometry method is closest to
2500
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Earth is number
3.
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 Neptune is closest to
30 degrees
The distance from our sun to the center of the Milky Way Galaxy is roughly
30,000 light years.
It now (2016) appears that, except for the universe itself, the largest structure in nature has a size of approximately
300 million light years.
The asteroid 2007 VK184 has one chance in 2940 of hitting the Earth between the years 2048 and 2057. The asteroid is 130 meters in diameter or about half the size of Apophis. Assuming that an impact could cause the death of 1,000,000 people the average death rate for this type of event is closest to
350 people per event
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.
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.
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Uranus is number
7.
Assume that the Hubble constant is 72 km/s/Mpc. If a galaxy is 10Mpc away, how fast is it moving away from us?
720km/s
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 degrees
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°.
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.
The fact that the surface of Mars shows no tectonic activity means that one of the requirements for continuing life might be missing.
A carbon-return process.
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.
If we should find micro-organisms on Mars that reproduce using a DNA/RNA scheme and set of amino acids that are mirror images of those used in all Earth life-forms, that would support the
Abiogenesis Model.
A multiple star system close to the Earth that is known to have stable orbits in the habitable zones of each of its stars is
Alpha Centauri.
The closest star to Earth (other than the Sun) is part of a multiple star system called
Alpha Centauri.
Titans atomosphere has....?
An atmosphere whose temperature and pressure permit liquid methane
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?
Any long-lasting technological civilization should be obvious and might even be visiting us, so where are they?
Which of these Mars rovers has been operating on the surface of Mars for six years so far (as of 2018).
Curiosity
Galaxies A and B are 100Mpc from us in exactly opposite directions while galaxy C is 200Mpc away in the same direction as galaxy B. From the viewpoint of galaxy A, we are moving away while
B and C both move away.
The Kuiper Belt is mostly located
Beyond the orbit of Neptune
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 the following types of object could reasonably be described as "dirty snowballs" or, for the larger ones, "flying icebergs?"
Comets.
In current Earth life, the self-copying molecule that contains the information needed to construct and operate a life-form is
DNA.
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.
A galaxy that is a featureless flattened ball of stars would be called a type
E7.
Which of the following systems do most living things on Earth now use to reproduce themselves?
Each DNA molecule splits in half and each half acts as a pattern to complete its other half.
The radiant of a meteor shower is the point in the sky that the
Earth is moving towards during the shower.
What we refer to as a "saturn ring-plane crossing" corresponds to what season on Saturn?
Fall or spring equinox
As of 2018, the search for near-Earth asteroids that could threaten global effects has most likely
Found more than 90% of them
The first spacecraft to go into orbit around Jupiter was
Galileo.
The temperature on Jupiter is
Much colder than anywhere on Earth.
Gerard Kuiper predicted that the region we now call the "Kuiper Belt" should be empty.
He was incorrect because he assumed a mass for Pluto that is now known to be too large.
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 to put it on a rising path and give it another speed boost when its distance from the Earth stops increasing.
It has been argued that hydrogen-powered automobiles can solve our energy problems because we can get all of the hydrogen that we need from sea water. Which of the following comments about the energy needed to separate the hydrogen and oxygen in water is correct?
It is the same as the energy released when the hydrogen is burned, so we get no net gain of energy.
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.
The New Horizons space probe made close approaches to
Jupiter and Pluto.
The most likely candidate for a second star in our Solar system was
Jupiter.
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 statements qualifies as a falsifiable working hypothesis of the sort that Karl Popper would favor?
Life arose on Earth and exists only there.
The Asteroid Belt is between the orbits of
Mars and Jupiter.
Which of the following statements best describes the presence of water on Mars?
Mars probably had liquid water flowing on its surface at some time in the past.
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.
An example of a planet which may occasionally have liquid water but retains an atmosphere of mostly carbon dioxide is
Mars.
You hear a loud noise outside and go outside to find a smoking rock embedded in your driveway underneath your wrecked car. The object is probably a
Meteorites
Changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis cause
Milankovich cycles.
Which of the following objects has a magnetic field whose North and South poles are displaced from its rotation axis poles and also from the center of the planet?
Neptune
Which of these planets has a rotation axis that is inclined in much the same way as that of Earth?
Neptune
As seen from far above the Earth's North Pole, the Earth orbits the Sun counter clockwise and
No planet orbits the Sun clockwise.
As seen from far above the Earth's South Pole, the Earth orbits the Sun clockwise and
No planet orbits the Sun counterclockwise.
Tycho Brahe's careful observations of the planets agreed, to within observational error, with
None of these systems.
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.
The Moon Charon orbits a point that is
Not inside Pluto at all.
Which of the following systems is closest to the plan of most current Earth life-forms?
One DNA molecule is used to make RNA molecules which, in turn make the proteins and enzymes that construct and operate a life-form.
Which of these Mars rovers operated on the surface of Mars for fourteen years?
Opportunity
The star Sirius can be located by using the pointer stars in
Orion.
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.
The first space probe to place a robotic rover on the surface of Mars was
Pathfinder.
Which of the following spacecraft were the first to fly past Jupiter?
Pioneer 10 and Pioneer 11
On Earth, a stable long-term carbon cycle could not exist without
Plate tectonics recycling the sea floor into the Earth's interior
The search for extrasolar planets has started to find "super-Earths," planets several times as large as Earth but with about the same density. From what we understand so far about plate tectonics on Earth, how likely is it that these super-Earths would have active surfaces like ours?
Possible if other conditions are also present.
Which of these was the Solar System model that assumed the Earth is 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.
A single sugar phosphate chain with nitrogenous bases attached along it describes a molecule of
RNA.
Which of the following features in the light reflected from a planet would indicate the presence of Earth-type plants (rather than just colored rocks) on its surface?
Red light is not reflected, but infra-red light is strongly reflected.
A galaxy with thick spiral arms and a large bar-shaped central bulge would be a type
SBa
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 hexagon-shaped pattern of clouds near its North Pole?
Saturn
Which of the following planets has a system of rings made of ice-covered rocks?
Saturn
Pioneer 11 was an early space probe sent to fly past
Saturn.
You would expect to see a waxing crescent Moon
Setting in the West right after the Sun.
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.
A technological civilization that lasts for astronomically significant periods of time should make an obvious and visible impact on the galaxy and should have figured out how to visit us by now. That leads to the question "So, where are they"? This statement and question is usually referred to as
The Fermi Paradox.
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.
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.
Suppose that some very strange creatures are found in a long-isolated place such as underneath the ice of Antarctica. Which of the following would be the strongest evidence that these creatures are descended from a different `first replicating molecule' than the rest of life on Earth?
The creatures use amino acid molecules that are mirror-images of the usual ones.
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.
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.
The motion of the Moon around the Earth causes
The phases of the Moon.
Suppose that you observe a planet that reflects mostly green light and absorbs both red and infra-red light. Which of the following conclusions can you make?
The planet does not have Earth-type green plants on its surface.
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.
The stars, as seen from the Earth, appear to be attached to
The stars, as seen from the Earth, appear to be attached to
The Viking Landers carried out several experiments on Martian surface soil. The final conclusion from those experiments (as interpreted at the time) was:
The surface of Mars is extremely hostile to all forms of organic matter
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.
Upon close examination by space probes, the rings of Saturn are found to consist of?
Thousands of circular rings
Which of the following planets or moons has an atmosphere with about 1.6 times the surface pressure of Earth's?
Titan
Which of these moons could have two levels of oceans, with oceans of liquid hydrocarbons on the surface and oceans of liquid water beneath the surface?
Titan.
Which of these moons has landmarks that are not rotating with the rest of the moon, indicating a subsurface ocean?
Titan.
Which of the following planets is about 4 times the size of the Earth?
Uranus
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
An example of a planet with no liquid water at all and a dense carbon dioxide atmosphere is
Venus
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 Cassini-Huygens spacecraft did what...?
Went into orbit around the planet Saturn
The Cassini-Huygens spacecraft
Went into orbit around the planet Saturn.
Which of these moons could have two levels of oceans, with oceans of liquid hydrocarbons on the surface and oceans of liquid water beneath the surface?
Which of these moons could have two levels of oceans, with oceans of liquid hydrocarbons on the surface and oceans of liquid water beneath the surface?
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
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.
The Earth's core consists of
a central core of solid iron and an outer core of liquid iron.
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.
Underneath a place where the sea floor is disappearing into a deep ocean trench, one expects there to be
a descending convection current in the Earth's mantle
It is expected that a normal Jovian planet, with no accidental encounters that could add or subtract moons, should have
a family of moons, all orbiting in the plane of the planets equator.
A sidereal day is
a few minutes shorter than a solar day.
Jupiter has
a few rings made of dark rocks.
When a hydrogen atom on one molecule is attracted to an oppositely charged part of another molecule, the result is
a hydrogen bond.
An encounter between Earth and an iron asteroid fifty meters in diameter would most likely cause
a large explosion on the ground.
Civilizations capable of sending out broadcast messages that we could possibly detect across interstellar distances would have to be technologically advanced and would probably be much more advanced than we are. That makes it difficult to decide what sort of signals they would send. The SETI program has decided to listen for microwave signals rather than more exotic types of signals (such as laser light, gamma rays, neutrinos, gravitational waves, etc.). The main reason for this choice is that
a microwave signal can send the largest amount of information for a given amount of energy used to generate the signal.
A rising convection current in the Earth's mantle is expected to cause
a mid-ocean ridge where tectonic plates are spreading apart.
How many stars similar to our sun would need to be collected at one place to equal the power output of Sgr A*?
a million: 1,000,000.
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.
The time it takes for the Celestial sphere to rotate once relative to the Earth is called
a sidereal day.
Light that has been spread out to show the frequencies or colors that are present is called
a spectrum.
The atmospheric pressure on the surface of Mars is
about 1% the surface pressure of Earth's atmosphere.
So far (as of 2018), the planet Venus has been visited by
about 28 successful space probes.
In comparison to the Copernican Theory, the Ptolemaic Theory made predictions that were of
about the same accuracy.
The ozone layer is where one finds
absorption of ultraviolet radiation.
Since 1990, the major spacefaring nations, Europe, China, Russia, Japan, India, and the U.S., have begun to return to the Moon. As of 2009, of these six space programs,
all except Russia have sent probes or orbiters to the Moon.
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).
Jupiter has
an atmosphere of Hydrogen and Helium with no real surface.
Neptune has
an atmosphere of Hydrogen and Helium with some methane.
Large numbers of protostars can be seen by using
an infra-red telescope.
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.
Here is the Drake Equation. In this equation, n_{e} stands for the
average number of habitable planets in a planetary system.
The tail of a comet always points
away from the Sun.
The tail of a comet always points
away from the sun
Jupiter failed to become a star because
because it has a starlike composition but lacks the nuclear
The objects of the Kuiper belt are mostly orbiting
beyond all of the Jovian planets.
A large asteroid impact can affect the Earth's climate primarily by
blocking the sunlight with its smoke and dust.
From the way that lunar eclipses happen, the Ancient Greeks were able to
calculate the distance from the Earth to the Moon.
A "rogue planet" or planetary mass objects that is not in orbit around any particular star
could be detected if its gravity magnifies the light from a star. that it happens to pass in front of.
Current computer models of planet formation suggest that the Alpha Centauri system
could have planets within the habitable zones of both Alpha Centauri A and Alpha Centauri B.
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.
According to our current (very tentative) estimates, a spaceship traveling 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.
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.
The orbit of Pluto
crosses the orbit of Neptune.
Copernicus said that the rotation of the Earth on its axis caused the
daily motions in the heavens.
Early (before 1970) theoretical estimates of the number of near-Earth asteroids were very low because the astronomers of that time
did not realize that Jupiter's gravity was deflecting asteroids from the Belt.
Far from the Sun, a comet is basically a
dirty lump of frozen gas and ice.
Europe and North America are
each on different plates and moving away from each other
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.
The atmosphere of Pluto is now known to
extend a thousand miles above its surface.
The semiliquid rock that is found inside the Earth
flows like a liquid under gradual pressure but is stiff like a solid under sudden pressure.
Carbon is essential for all life we know about because it
forms complex compounds.
Which of the following types of radiation has the highest frequency on this list?
green light.
The absorption and re-radiation of infrared light by gases such as carbon dioxide is the key process in the
greenhouse Effect.
The range of distances of a planet from its primary star that will permit the existence of liquid water on the planet's surface is called the
habitable zone.
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.
The moon Miranda is peculiar because it
has a surface feature that looks like a giant check mark.
If we detect that a star is sometimes moving toward us and sometimes moving away and also find that this pattern repeats at regular intervals, we know for sure that the star
has at least one object of unknown type orbiting around it.
The Big Bang Theory predicts that most of the dark matter in our galaxy and elsewhere must consist of something other than the known chemical elements. This prediction
has been tested by looking for rogue planets.
The rotation rate of Saturn
has not been exactly determined because different methods give somewhat different results.
The side of the Moon that faces away from the Earth
has only a few small lunar maria.
Cepheid variable stars with the same luminosity usually
have similar periods.
If we detect that the intensity of the light from a star is mostly constant but drops slightly to a new constant value for a while and then returns to its normal level and repeats this behavior at regular intervals, we can reasonably suspect that
he star has a planet in orbit around it.
Which of the following types of radiation has the second lowest frequency on this list?
heat radiation.
The second most common element in the universe is
helium.
The reason the temperature rises as you go higher in the thermosphere is that the Sun's
high energy particles heat the ionosphere.
The molecules of both water ice and liquid water are attached to one another by
hydrogen bonds --- .Different parts of each molecule have opposite charges.
The Kuiper Belt is thought to have originated when
icy objects condensed out just beyond Neptune
The Kuiper Belt is thought to have originated when
icy objects condensed out just beyond Neptune.
The stars of the Milky Way are mostly found
in a band of stars stretching across the sky.
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.
If there is life on one of the Jovian moons, we would expect that life to most likely be
in the subsurface oceans, using chemical and thermal energy.
One indication that there is a lot of invisible matter in the outer halo of our galaxy is that stars in that region orbit with velocities that
increase with increasing distance from the center.
Protostars are very bright because of their large surface areas. Most of this energy comes out as
infra-red light with wavelengths too long to see with an ordinary telescope.
Which of the following types of radiation has the second lowest frequency on this list?
infrared light
The portion of the Earth that is solid iron and nickel is the
inner core.
Seismic waves are used to determine the Earth's
interior structure.
If the frequency of electromagnetic radiation goes from 9×10¹⁴Hz to 3×10¹⁴Hz, 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 frequency of electromagnetic radiation goes from 2×10¹⁴Hz to 6×10¹⁴Hz, the energy of each individual photon in the radiation
is multiplied by 3
If the frequency of electromagnetic radiation goes from 3×10¹⁴Hz to 9×10¹⁴Hz, the energy of each individual photon in the radiation
is multiplied by 3.
The range of signal frequencies between absorption bands caused by hydrogen and hydroxyl molecules
is referred to as the "water hole" and is the frequency band that SETI programs usually choose.
The gravitational attraction of the Earth for other objects,
is smaller for objects farther from the Earth but never vanishes entirely.
Pluto
is sometimes closer to the Sun than Neptune and sometimes farther from the Sun.
The constellation Sagittarius is where the Milky Way
is thickest.
The photosphere of a protostar
is where light is last scattered
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.
One reason that the Copernican System failed to fit Tycho's observations was that
it used circular orbits instead of ellipses.
A planet larger than Mars would be a good place to look for life because
it would have more surface area than Mars.
Icy objects condensed from the outskirts of the Solar Nebula to form
the Kuiper belt.
The main reason to suspect that Titan has a subsurface ocean of water is
landmarks that are not rotating with the rest of the moon.
If we wish to find life with a carbon-return process similar to the one here on Earth, we should look for planets
larger than Mars.
As compared to higher frequency electromagnetic radiation, lower frequency electromagnetic radiation will usually cause
less damage.
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.
The eclipse or transit photometry method of searching for exoplanets can be expected to find
less than one out of every 10 exoplanets.
Compared to the rest of the Lunar surface, the Lunar Maria are
lower and younger.
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.
Comparing asteroids hitting the Earth at the same speed, the energy released by an asteroid impact is proportional to (Be careful here!) the
mass of the asteroid.
The motions of the stars near Sgr A* make it possible to determine its
mass.
The mass that is distributed in different parts of our Milky Way Galaxy is estimated by
measuring how stars orbit the center of the galaxy.
The debris of long-dead comets causes
meteor showers.
When the fireball of its entry into the atmosphere was spotted from a KLM airliner, asteroid 2008 TC₃ had officially become a
meteor.
Near the center of the Milky Way there is an intense radio source whose mass is approximately three
million solar masses within several light days of the center.
As the two foci of an ellipse are moved apart, the shape of the ellipse becomes
more like a line between the foci.
In comparison to RR Lyra variables, Cepheid variable stars are
more luminous and less common.
Because different molecules vibrate with distinctive radio frequencies, it is possible for radio telescopes to identify the chemical compounds that are present in interstellar clouds. When they look for complex compounds (more than four atoms) they find
mostly carbon compounds.
Comets that originate in the Inner Oort Cloud would be expected to have orbits that are
mostly close to the plane of the solar system
The gravitational influence of the planets causes asteroids to
move from the asteroid belt into the inner solar system.
In a spiral galaxy, long-lived stars such as our Sun
move in and out of spiral arms.
In one day, the position of the Sun on the Celestial Sphere
moves eastward along the ecliptic by 1°.
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.
In the Earth's atmosphere, the amount of carbon dioxide is
much less than the typical amount of water.
The observation that stars farther from the center of our galaxy orbit faster is thought to mean that
much of the mass is outside the central bulge.
According to the definition of "habitable zone" that we are using, Earth is
near the inner edge of the habitable zone of our Solar System.
Within the Local Supercluster, our Local Group of galaxies is
near the outer edge of the cluster.
As seen from North America, the constellation Casseopeia
never sets.
One of the experiments carried out by the Viking Landers was to use a mass spectrometer to analyze the gas given off from a heated soil sample. The results of that experiment (as interpreted at the time) established that Martian soil contains
no carbon compounds at all.
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 Viking Landers carried out several experiments on Martian surface soil. One of those experiments, the Pyrolytic Release Experiment gave a positive result for the presence of life forms. That result was interpreted to mean
nothing because a sterilized control sample gave the same result.
Here is the Drake Equation. In this equation, N stands for the
number of communication-capable civilizations in our galaxy.
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.
Population I stars in our galaxy include
only younger stars such as our sun.
The Population II stars of our Milky Way
orbit the central bulge in all directions.
The Doppler shift of familiar spectral lines from gas clouds and stars in our galaxy measures their
orbital velocities within the galaxy.
A ring galaxy such asHoag's Object that is the result of a collision would be classified as a
peculiar galaxy.
The part of a protostar where the density first becomes low enough for light to escape is called the
photosphere.
It has been theorized that planets do not easily form in binary star systems. If they do form, there are three possible arrangements:(1) Planets with orbits similar in radius to the distance between the two stars.(2) Planets with orbits much smaller in radius than the distance between the two stars.(3) Planets with orbits much larger in radius than the distance between the two stars.Observations so far (2018) indicate that
possibilities (2) and (3) actually happen.
When a seismometer detects an earthquake, the first signal to arrive is usually the
pressure wave
When a seismometer detects an earthquake, the first signal to arrive is usually the
pressure wave.
By making extensive observations of planetary motion, Tycho Brahe
provided accurate data for the first time.
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.
Shear waves normally propagate
slower than pressure waves.
The Kepler Spacecraft was designed to measure
small changes in starlight from nearby stars.
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.
Extragalactic nebulae such as the Great Nebula in Andromeda were not immediately recognized as galaxies similar to our own Milky Way because they were thought to be
smaller, nearby objects.
The stratosphere is where one finds
smoke and dust lingering for years.
A large asteroid impact causes the extinction of whole species mainly by the effects of the
smoke and dust. it blocks the sunlight
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.
Aristotle said that the amount of force on a moving earthly object determines its
speed
In a region of the atmosphere in which the temperature rises with increasing altitude
stratosphere
The layer of the atmosphere that tends to retain dust and smoke for long periods of time is the
stratosphere.
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 molecules of both liquid water and ice are held together by
the attraction between the hydrogen atoms on one water molecule and the oppositely charged oxygen atom on another.
An astronomical unit is defined to be
the average distance from the Earth to the Sun.
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.
The recoil or 'kick' of a gun that is firing a bullet is a force exerted on the gun by
the bullet.
The Local Group is what astronomers call
the cluster of galaxies that our galaxy belongs to.
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.
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.
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 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.
The first major failure of the Ptolemaic Theory to predict the results of observations was
the phases of Venus.
Mars retains a carbon dioxide atmosphere because
the pressure is very close to the triple point of water.
Compared to the frequency of photons absorbed during a transition from a from a -6ev state to a -4ev state, transitions from the -5ev state to a -3ev state would correspond to absorbing photons whose frequency is
the same
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
the same because gravity pulls on it more strongly and it has more inertia.
The Moon rotates on its axis so that it always keeps
the same side (its far side) pointed away from the Earth.
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.
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.
Our sun is roughly at the center of
the visible part of the Milky Way.
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.
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.
You hear about an asteroid impact threat at level 10 on the Torino Scale. You should
think about ways to get off the planet.
The magnetic field of Jupiter is
tilted relative to the planet's rotation axis but not offset from its center.
The two hydrogen atoms in a water molecule are both attached
to the oxygen atom, but offset so that the molecule looks bent.
A planet that is following Kepler's Laws, accelerates
toward the Sun.
In which of these layers of the atmosphere is it generally colder at higher altitudes?
troposphere.
The Alpha Centauri star system consists of
two stars in close orbit around each other and a third star orbiting farther out.
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.
The Surface of pluto can best be described as?
varied with ice mountains and almost no craters at all.
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.
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 it takes it out of the atmosphere
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.