FINAL Flashcards
(180 cards)
1
Q
The solar system is believed to have formed from
A. the gas in a disk around a black hole.
B. the debris thrown out by a supernova explosion.
C. a hot nebula of ionized gas.
D. a cool nebula of gas and dust.
A
D. a cool nebula of gas and dust.
2
Q
Astronomers estimate that the solar nebula from which the solar system formed began as a cloud that was approximately _____ in diameter.
A
1000 au
3
Q
The Kuiper belt is
A
Located beyond the orbit of Neptune
4
Q
When a rotating cloud of gas and dust contracts gravitationally, conservation of angular momentum causes its speed of rotation to
A
increase
5
Q
The nebular hypothesis of the formation of the solar system assumes that the material that became the solar system began as a large spherical cloud of gas and dust, rotating slowly. As the solar system formed, most of this material was transformed into a compact, flattened disk, rotating more rapidly. What is the explanation for this change in shape and rate of rotation?
A
conservation of angular momentum
6
Q
In the early solar system, the boundary beyond which gases and ices of water, ammonia, carbon dioxide, etc., were able to persist is called the _____ line.
A
snow
7
Q
One aspect of the solar system that astronomers believe makes it unique from other exoplanet systems discovered so far is that _____.
A
our early gas giants stabilized their orbits and didn’t spiral in toward the Sun
8
Q
The protostar at the center of the forming solar system glowed hot, the gases warmed after gaining kinetic energy falling into the mass of the protostar, NOT from _____ at the core.
A
nuclear fusion
9
Q
Which of these describes what happens to a comet in a highly elliptical orbit as it passes near the Sun.
A
The ices that are normally frozen in the nucleus of the comet begin to melt, becoming a gas that is then driven away by the solar wind into a long tail.
10
Q
Under the pull of gravity, if an object has a large enough mass, astronomers expect that it will be _____ in shape.
A
round
11
Q
Consider a hypothetical new object that astronomers have found in orbit around Saturn. This object has a diameter of 3000 km. How would astronomers categorize this object?
A
a moon of Saturn
12
Q
Consider a hypothetical new object that astronomers have found in the solar system. This object has an orbit that places it between Mars and Jupiter, and it has an approximate diameter of 1000 km. How would astronomers categorize this object?
A
dwarf planet
13
Q
The characteristic that is NOT true of the terrestrial planets is:
A
a relatively low density compared to the Jovian planets.
14
Q
The characteristic that is NOT shared by all giant planets is
A
heavily cratered surfaces.
15
Q
The majority of the 175 known planetary moons in the solar system are NOT _____ in shape.
A
spherical
16
Q
If astronomers were to detect an exoplanet and calculate its average density to be about 5500 kg/m3, what could they conclude about this exoplanet?
A
This exoplanet is likely a terrestrial planet
17
Q
What aspects of a planet tend to contribute to a large albedo?
A
cloud cover
18
Q
If astronomers discovered an exoplanet with a mass 300 times that of Earth but orbits its star beyond the snow line, what aspect about the planet could astronomers likely assume about the planet even if they cannot presently detect evidence of it?
A
This planet could likely have a significant number of satellites in orbit around it.
19
Q
Earth’s atmosphere was not always nitrogen-rich and oxygen-rich, the way it is now. What were the primary constituents of Earth’s atmosphere prior to the atmosphere today during the first 300 million years or so of its existence?
A
carbon dioxide and water vapour
20
Q
The greenhouse effect occurs because:
A
some gases absorb infrared radiation.
21
Q
If astronomers found a planet with a large concentration of _____ gas in its atmosphere, its presence would be a good indicator that some form of life exists on that world.
A
oxygen
22
Q
If astronomers were looking for certain compounds in the atmosphere of an exoplanet, which compound would MOST likely indicate the presence of life on that planet?
A
oxygen
23
Q
Which of these would NOT be a result if Earth’s interior had cooled significantly since its formation?
A
Earth’s atmosphere would be much thicker than currently.
24
Q
The majority of the mountains seen on the Moon were created by:
A
major impacts early in the Moon’s history.
25
A _____ is a lava floodplain covering the floor of an ancient asteroid impact basin.
mare
26
What would astronomers expect to be true of the Moon if the capture theory of formation had been correct?
The composition of the Moon should be significantly different from that of Earth in terms of chemistry and density.
27
Which of these is a problem that astronomers have with the giant impact theory for the creation of the Moon?
The Moon should have a measurable mix of content from both Earth and Theia, which likely would have formed elsewhere in the solar system.
28
Why are the rocks that the Apollo astronauts found on the Moon so much older than typical rocks found on the surface of Earth?
The surface of the Moon has not undergone the same tectonic activities that generate new crust on Earth.
29
If astronomers observe a crater on the Moon with bright ejecta only visible radiating from the eastern side of a crater, what could they conclude about the formation of this crater?
This is a relatively young crater created by a meteoroid impacting from the west of the impact site at a shallow angle.
30
Astronomers have calculated that the rate at which the Moon is moving away from Earth is approximately 3.8 _____ per year.
centimetres
31
The synchronous rotation of the Moon can be explained by _____ forces that Earth exerted on the Moon when it was still molten and orbiting much closer to Earth.
tidal
32
If the tidal forces that Earth exerted on the Moon helped to put it into a synchronous rotation, why haven't the tidal forces that the Moon exerts on the oceans put Earth into a synchronous rotation as well?
They are in the process of putting Earth in a synchronous rotation, but the process will take billions of years
33
For what percentage of one complete lunar cycle is ANY part of the far side of the Moon visible from Earth?
almost none of the time
34
The Apollo astronauts deposited certain _____ on the surface of the Moon that allowed astronomers back on Earth to get accurate measurements on the distance between Earth and the Moon over an extended period of time to see how that distance changed.
reflectors
35
The rotation of Earth is slowing due to the energy it loses to friction during the tides and it slows down by about one-thousandth of a second each century. How much longer will a day on Earth be 1 billion years from now?
3 hours longer
36
The process by which gasses trapped in rocks below the surface are released into Mercury's thin atmosphere is known as _____.
Outgassing
37
A small planet or satellite would be expected to have all of these characteristics EXCEPT:
a large iron core
38
Which of these would be a likely result if Mercury exhibited synchronous rotation rather than the 3-to-2 spin orbit coupling that it currently has?
The temperature difference between day and night would be greater.
39
Which of these is NOT a reason that astronomers know the scarps on Mercury formed some time later in the history of the planet?
Astronomers have been able to use radiometric dating on rocks collected near the scarps to determine their age.
40
Which of these would NOT be likely to happen if Mercury had a mass closer to that of Earth's?
Mercury would no longer exhibit its 3-to-2 spin-orbit coupling.
41
The highest temperature on Mercury is 700 K, which is 50 K less than the highest temperature on Venus. How, then, can Mercury experience the greatest temperature range in the solar system? Which of these does NOT contribute to this great range of temperature?
The ice near the poles contributes to the very cold night temperature.
42
The surface of Venus consists primarily of:
rolling plains and low hills with two major, continent-size highland regions.
43
A group of colleagues claim they saw Venus rising in the east as the brightest object in the sky just as the Sunset. They are wrong because:
Venus never rises at sunset.
44
Suppose Venus had no greenhouse effect. The amount of infrared energy radiated by Venus toward space would be:
the same as is the case now.
45
If one compares Venus's atmosphere to that of Earth, one finds that the temperature in the atmosphere of Venus decreases smoothly with increasing altitude all the way from the surface (hottest) to the outermost parts of the atmosphere (coolest), whereas the temperature in Earth's atmosphere at first decreases, then increases, then decreases again, with increasing altitude. What is a reasonable interpretation of these observations?
Venus has essentially no ozone in its atmosphere.
46
The yellowish color of Venus's permanent cloud cover is due to the presence of _____ in the atmosphere.
sulfur
47
If the altitude of the clouds on Venus were compared to clouds on Earth, Venus's clouds would reside mainly in the equivalent of Earth's layer of atmosphere called the _____.
stratosphere
48
How long ago do astronomers believe that Mars tectonic plate activity stopped?
4 billions years ago
49
Which of these features are NOT something that observers have claimed to have seen on the surface of Mars over the years that have led to wild speculations about alien civilizations living there?
regular city block—like structures
50
Astronomers have many reasons to believe the northern hemisphere of Mars has experienced more geologic activity than the southern hemisphere. Which of these is NOT one of those reasons?
The Martian magnetic field is oriented north to south, opposite Earth's magnetic field.
51
Mars has the longest _____ period of all the planets in the solar system as viewed from Earth because it moves such a significant distance through its own orbit during the course of one year on Earth.
synodic
52
A popular science fiction book and movie imagines a hypothetical crewed mission to Mars that ends in tragedy when a dust storm forces the astronauts to abandon one their crew members on the surface of Mars during an evacuation. What is the problem with this scenario?
The wind in a Martian dust storm is very weak in comparison to an Earth storm.
53
Why does Mars have the longest synodic period of any planet in the solar system?
because Mars moves a sizable distance through its orbit in one Earth year
54
What is the Kelvin—Helmholtz mechanism?
the release of gravitational potential energy as heat when a body contracts and cools
55
Each of these is a result of Comet Shoemaker-Levy 9 impacting Jupiter EXCEPT:
the comet fragments disappeared into Jupiter's atmosphere without leaving a trace.
56
The fine dust particles that make up the rings of Jupiter are constantly being pushed out of orbit by the pressure of radiation from Jupiter and from the Sun. These ring particles are being replenished by particles from the _____ of Io and regolith from the smaller inner moons.
volcanoes
57
Astronomers notice that a certain region of Ganymede appears to have fewer craters, and shows signs of tectonic activity, as opposed to adjacent more heavily cratered areas. What can astronomers conclude about this region?
The region is original to Ganymede's surface.
The region is much older than the surrounding cratered areas.
The region is much younger than the surrounding cratered areas.
Nothing much can be determined about this region based on this information.
The region is much younger than the surrounding cratered areas.
58
If life did exist deep under Europa's icy crust in its subsurface ocean, where would these organisms MOST likely derive their energy from?
from the intense magnetic field of nearby Jupiter
from charged particles in the deeper portion of Europa's oceans
from sunlight that filters down through the thin icy crust
small volcanic vents on the floor of Europa's ocean
small volcanic vents on the floor of Europa's ocean
59
Future missions have been proposed to explore the subsurface oceans of Europa with a robotic probe. Which of these is NOT a unique problem that astronomers would have to consider on such a mission?
drilling through a layer of ice of unknown thickness
potentially contaminating the ocean with Earth organisms
landing a probe for the first time on the moon of another planet
operating a submersible robotic probe in an alien ocean
landing a probe for the first time on the moon of another planet
60
What have astronomers observed about the ice geysers on Enceladus?
The geysers produce more eruptions when the moon is in a synchronous orbit with Saturn.
The geysers are most active when the moon is closest to Saturn.
The geysers are constantly and randomly ejecting particles into orbit.
The geysers are most active when the moon is farthest from Saturn.
The geysers are most active when the moon is closest to Saturn.
61
The atmosphere of Titan, the largest satellite of Saturn, is mostly nitrogen with a significant amount of _____.
methane
62
Why are almost all of Saturn's rings inside its Roche limit?
The gravitational pull of Titan keeps any material from accumulating outside the limit.
Nothing new has fallen past the Roche limit to replenish the rings.
Outside the Roche limit, particles can clump together to form larger objects.
That location is where the object that created the rings was destroyed.
Outside the Roche limit, particles can clump together to form larger objects.
63
About 10 times as much gas lies above each square meter of Titan's surface than lies above a square meter of Earth's surface. So how does the atmospheric pressure on the surface of Titan compare to atmospheric pressure at Earth's surface?
It must be 10 times Earth's pressure.
Comparing the pressure to the size of the body, it must be more than 10 times Earth's pressure.
Titan's gravity is weaker, so it will be less than 10 times Earth's pressure.
It is not possible to predict the answer from the information given.
Titan's gravity is weaker, so it will be less than 10 times Earth's pressure.
64
Consider a team of astronauts taking a hypothetical dive in Saturn's atmosphere. How would such a dive NOT be different on Saturn when compared to the same dive on Jupiter?
The transition between gaseous atmosphere and liquid hydrogen occurs at a well-defined barrier on Saturn.
The astronauts would experience helium rain falling around them.
The wind speeds at the upper atmosphere would be much greater than those on Jupiter.
The dive through the gaseous atmosphere would take much longer before reaching liquid hydrogen.
The transition between gaseous atmosphere and liquid hydrogen occurs at a well-defined barrier on Saturn.
65
Neptune was discovered in 1846 by _____.
Johann Galle
Urbain Leverrier
John Couch Adams
William Herschel
Johann Galle
66
Which planet has the fastest measured wind speeds in the solar system?
Jupiter
Saturn
Uranus
Neptune
Neptune
67
Due to the extremely cold 73 K temperature at the top of Uranus's atmosphere, the clouds there are composed of _____ ice crystals.
methane
68
Comparing the two ice giants, Neptune has a greater mass but Uranus has a greater size. What can be said about the two planets that reconciles this discrepancy?
Uranus is made out of more gaseous material.
Neptune is made out of heavier elements.
Neptune has a greater density because of its greater gravity.
Uranus's core is denser than Neptune's, but its atmosphere is less dense.
Neptune has a greater density because of its greater gravity.
69
Suppose an instrument probe is floating under a balloon in the southern hemisphere of Uranus at the time of midwinter in Uranus's southern hemisphere. What is the farthest south of Uranus's equator that the probe could be and still be able see the Sun for at least part of the day?
23.5 degrees south of the equator
66.5 degrees south of the equator
8 degrees south of the equator
82 degrees south of the equator (8 degrees from the south pole)
8 degrees south of the equator
70
Neptune was discovered because of its influence on Uranus's orbit. At what point in those planet's orbits were the observations likely made that led to Neptune's discovery?
Neptune was close to opposition as seen from Uranus.
Neptune was close to conjunction as seen from
Uranus.
Uranus was close to opposition as seen from Neptune.
Uranus was close to conjunction as seen from Neptune.
Neptune was close to opposition as seen from Uranus.
71
The largest asteroid in the inner solar system is named _____, which is also classified as a dwarf planet.
Ceres
72
No comets exist in the asteroid belt between Mars and Jupiter because the asteroid belt is inside the Sun's _____.
snow line
73
What is one of the more unusual facts about Pluto and its moons?
All of Pluto's moons have a retrograde orbit around the dwarf planet.
Pluto has more moons orbiting it than the larger terrestrial planets.
Both Pluto and all of its moons have very tenuous atmospheres.
Pluto was able to gravitationally capture all these moons.
Pluto has more moons orbiting it than the larger terrestrial planets.
74
The only planet with a planet-to-moon mass ratio that is even close to that of Pluto and Charon would be _____.
Earth
75
As most asteroids are observed, they seem to vary regularly in brightness. Which of these statements explains why?
Different surface features scatter different amounts of sunlight as the asteroid rotates.
Most asteroids are volcanic, and large sections of an asteroid are typically covered with glowing lava.
Asteroids are in synchronous orbits around the Sun, with Sun-facing sides composed of rock and "dark" sides covered with ice. When one sees the back side, less reflection is seen than when the Sun-facing side is seen.
Because there are so many asteroids, they are constantly passing into and out of each other's shadows.
Different surface features scatter different amounts of sunlight as the asteroid rotates.
76
Which region of the solar system does NOT include at least one dwarf planet?
the Oort cloud
the Kuiper belt
inside Mars's orbit
the asteroid belt
inside Mars's orbit
77
What significant findings did the Rosetta spacecraft uncover about the water content on Comet Churyumov-Gerasimenko?
The water was almost perfectly pure and had no other compounds dissolved in it.
The total amount of water on the comet was significantly less than what astronomers predicted.
The isotope ratio of the cometary water was very different from that on Earth.
The water's deuterium ratio of the water on the comet was just a little lower than on Earth.
The isotope ratio of the cometary water was very different from that on Earth.
78
The orbits of classical KBOs in the Kuiper belt extends from 30 au (near the orbit of Neptune) outward to _____ au.
50
79
What would be the fate of a comet that had an orbit with aphelion at about 2.0 au and perihelion at 0.5 au?
It would orbit the Sun and periodically warm up, create a tail, then refreeze as it moved to aphelion.
It would never fall in toward the Sun to create a tail visible from Earth.
It would never stop outgassing and would very quickly lose all its ices and eventually fall apart.
It would only show a moderate coma and tail and would last a very long time.
It would never stop outgassing and would very quickly lose all its ices and eventually fall apart.
80
Consider a comet with an orbital period of 80 years that was first documented 1600 years ago. Astronomers would expect this comet to continue its visits to the inner solar system for another _____ years.
6400
81
If a comet enters the inner solar system with an orbital plane far from the plane of the ecliptic, it probably originated:
in the Oort Cloud.
82
When the Rosetta spacecraft studied Comet Churyumov-Gerasimenko, it found that the ratio of _____ isotopes of water were about 3 times higher than are typically found on Earth.
deuterium
83
What type of meteorite was the Allende meteorite?
carbonaceous chondrite
84
How do astronomers estimate the actual number of meteorite falls and their types (stony, iron, or stony-iron)?
They count the number of each type of meteorite that has been discovered across Earth.
Astronomers survey the icy polar regions of Earth where no other terrestrial rocks are typically found.
They survey the sky watching for meteors to catalog each type that enters the atmosphere.
They survey the solar system using telescopes and probes to count the number and types of meteorites.
Astronomers survey the icy polar regions of Earth where no other terrestrial rocks are typically found.
85
Why do geologists suspect that the Great Dying, the mass extinction event associated with the end of the Permian period, coincides with a celestial impact like the one that ended the dinosaurs?
Evidence has been uncovered of massive volcanic activity corresponding to the end of the Permian period.
Fullerenes have been discovered with celestial gases trapped in them that could only have been created by a supernova.
A 250-million-years-old crater has been discovered off the coast of Australia that dates to the end of the Permian period.
Another iridium layer was found deeper underground than that associated with the extinction of the dinosaurs.
Another iridium layer was found deeper underground than that associated with the extinction of the dinosaurs.
86
In addition to the large iron content, iron meteorites are usually between 10 and 20 percent _____ by weight.
nickel
87
What tends to be the best time to view meteor showers?
at midnight
at dawn
early evening
an hour or two before dawn
an hour or two before dawn
88
What information do astronomers NOT need to predict a meteor shower?
where source comet's orbit intersects Earth's orbit
the orbital inclination of the comet's orbit
the constellation that the Sun will be in when Earth crosses the debris field.
where the greatest concentration of debris is in the comet's orbit.
the constellation that the Sun will be in when Earth crosses the debris field.
89
For most meteor showers, the most active times are after midnight, but the peak of the shower is usually an hour or two before _____.
dawn
90
The _____ forms the visible surface of the Sun.
photosphere
91
Many images of the chromosphere are taken through filters. One reason for this is:
to allow through the filters the light produced most strongly by the chromosphere.
to ensure that the blue of Earth's atmosphere does not interfere with the image.
to allow through the light that is produced predominantly in the photosphere.
to block out all light produced in the corona.
to allow through the filters the light produced most strongly by the chromosphere.
92
As one looks into the Sun from Earth, the layers that are observed in the solar atmosphere (in order from the outside inward) are:
corona, chromosphere, photosphere.
photosphere, chromosphere, corona.
corona, photosphere, chromosphere.
chromosphere, corona, photosphere.
corona, chromosphere, photosphere.
93
The granules observed under excellent observing conditions on the visible surface of the Sun are:
the tops of columns of rising and falling gas in the layer below the photosphere.
cooler, darker regions where the Sun's magnetic field is particularly intense.
columns of gas rising through the Sun's chromosphere.
waves created by oscillations in the solar interior, with periods between 5 and 20 minutes.
the tops of columns of rising and falling gas in the layer below the photosphere.
94
The layers of the Sun's atmosphere, from inside to outside, are:
chromosphere, corona, photosphere.
photosphere, chromosphere, corona.
photosphere, corona, chromosphere.
corona, photosphere, chromosphere.
photosphere, chromosphere, corona.
95
The photosphere is cooler than the chromosphere. How does this influence the spectral characteristics of the Hα line, the prominent red line in the hydrogen spectrum?
This line is an emission line in the chromosphere but an absorption line in the photosphere.
This line is an absorption line in the chromosphere but an emission line in the photosphere.
Both the chromosphere and the photosphere show absorption lines for Hα, but the lines are darker and broader in the photosphere.
Both the chromosphere and the photosphere show absorption lines for Hα, but the lines are darker and broader in the chromosphere.
This line is an emission line in the chromosphere but an absorption line in the photosphere.
96
The gas at the outer edge of a granule is darker than the gas at the center because:
it is moving toward the observer.
it is hotter than the gas at the center.
it is cooler than the gas at the center.
it is moving away from the observer.
it is cooler than the gas at the center.
97
A _____ is the name given to a brighter region in the chromosphere often associated with a sunspot group on the photosphere below it.
plage
98
X-ray observations of the corona reveal lighter and darker spots, the latter indication where the corona is cooler. These darker spots are the source of:
granules.
spicules.
sunspots.
coronal mass ejections.
coronal mass ejections.
99
The source of the steady solar wind, part of which streams past Earth at about 400 km/s, is:
granulation, where hot, convecting gas from the solar interior rises into the photosphere.
solar flares, highly energetic outbursts that occur near sunspots.
coronal holes, regions of the corona with a lower temperature than the rest of the corona.
prominences, bright arches of gas that occasionally erupt upward.
coronal holes, regions of the corona with a lower temperature than the rest of the corona.
100
Is there a connection between plages and sunspots?
Yes, the 5-minute oscillations of the photosphere push the sunspots up into the chromosphere every 5 minutes, and thus results in plages.
Yes, the magnetic fields that result in sunspots in the photosphere continue on up through the chromosphere, where they produce plages.
Yes, the magnetic fields that result in sunspots in the photosphere compress the gases above the photosphere, and this pressure creates plages in the chromosphere.
No, sunspots are a photospheric phenomenon while plages occur in the chromosphere.
Yes, the magnetic fields that result in sunspots in the photosphere compress the gases above the photosphere, and this pressure creates plages in the chromosphere.
101
When the Sun oscillates, a region of gas alternates between moving toward Earth and moving away from Earth by about 10 km. When the gas is moving toward Earth its light is:
dimmer.
brighter.
redshifted.
blueshifted.
blueshifted.
102
Suppose a reversal of the Sun's magnetic field has just occurred and the north magnetic pole is now at the north rotation pole. In about _____ years a reversal will again bring the north magnetic pole to the north rotation pole.
22
103
How are solar vibrations observed?
Solar vibrations manifest themselves in periodic Doppler shifts when one examines the solar surface.
Solar vibrations are visible only during a solar eclipse when one can see pulses of energy being pumped into the solar atmosphere by the vibrations.
Detectors of sound waves are mounted on satellites in orbit around Earth.
Longer-period vibrations, like the 5-minute oscillations, can be seen as up-and-down movement of the Sun's surface by carefully watching the edge of the Sun.
Solar vibrations manifest themselves in periodic Doppler shifts when one examines the solar surface.
104
Albert Einstein found that matter could be converted into _____.
energy
105
The young Sun had a core containing less helium and more hydrogen than it has now. Each of these is a consequence of this EXCEPT that compared to the present Sun, the young Sun was:
less luminous.
cooler in its core.
less massive.
smaller.
less massive
106
The second most common element in the Sun is_____.
helium
107
In the first step of the proton-proton chain, a positron is produced. What happens to the positron?
It annihilates with an electron to produce a gamma-ray photon.
It becomes part of a helium atom.
It becomes part of a hydrogen atom.
It escapes from the Sun.
It annihilates with an electron to produce a gamma-ray photon.
108
Why does the Sun's atmosphere heat so dramatically in the transition zone between the chromosphere and the corona?
This transition zone is the only region of the Sun, in addition to the core, where nuclear reactions take place.
The twisted magnetic field traps heat at this location.
Ozone absorbs ultraviolet radiation at this level, just as in Earth's atmosphere.
This question is, at present, unanswered.
This question is, at present, unanswered.
109
What is a difficulty in attributing the energy source of the Sun to things other than nuclear reactions, such as combustion or gravitational contraction?
that other sources of energy do not work in the vacuum of space
that reliance on other sources of energy requires the Sun to be unreasonably young
an absence of other reasonable sources of fuel
an absence of alternative ideas
that reliance on other sources of energy requires the Sun to be unreasonably young
110
If one was to shade oneself from the Sun with an umbrella of 1 m2 area (held perpendicular to the Sun's direction), how many solar neutrinos would pass through the umbrella every second?
25
10 billion (1010)
300 million (3 x 108)
1000 million million (1015)
111
The Sun's corona is much hotter than the photosphere, but it is not as bright because
the granulation on the photosphere allows it to generate more energy.
the coronal holes allow more light from the photosphere to pass through.
the photosphere has a much stronger magnetic field and is therefore brighter.
the corona contains fewer particles and does not have as much energy as the photosphere.
the corona contains fewer particles and does not have as much energy as the photosphere.
112
In 2009, at solar minimum, there were only three sunspots visible during the year. What would be the next year you would expect to observe about the same number of sunspots?
2020
2109
2014
Never again
2020
113
which latitudes on the sun is the rotation rate the slowest
62° S
The rate is the same for all latitudes.
23° N
12° S
62 S
114
What causes the Sun's magnetic field to become tangled?
Different latitudes of the Sun rotate at different rates, causing the magnetic field to become tangled.
The Sun rotates as a rigid body, causing the magnetic field of the Sun to interact with itself.
The magnetic field lines of the Sun are shifted due to Mercury's strong magnetic field and fast orbital speed.
Sunspots cause the magnetic field lines to become fixed in place while the rest of the Sun rotates.
Different latitudes of the Sun rotate at different rates, causing the magnetic field to become tangled.
115
What is the difference between a solar filament and a solar prominence?
A prominence turns into a filament as it cools and becomes a darker color.
A filament and prominence are the same feature, only seen from different perspectives.
A prominence can only be seen on the Sun during active periods while filaments can be observed at any point in the
solar cycle.
A prominence is a feature that can only be observed at ultraviolet frequencies and a filament can only be observed at
infrared frequencies.
A filament and prominence are the same feature, only seen from different perspectives.
116
Sunspots exhibit temperatures of about 4000 K which is significantly below the temperature of the Sun's photosphere (5000 K). Why are sunspots so much cooler compared to the rest of the Sun's surface?
Opaque material within sunspots reflects heat away from them.
The sudden decrease of pressure due to flares from sunspots reduces their surface temperature.
Strong magnetic fields inhibit the flow of hot plasma into sunspots.
Sunspots are regions of high density material, which slows the motion of particles within them.
Weak electric fields within sunspots inhibit the flow of hot plasma into sunspots.
Strong magnetic fields inhibit the flow of hot plasma into sunspots.
117
Each second, the Sun's mass
Increases
Does not change
Decreases
Decreases
118
Choose the correct statement regarding energy production in the interior of a star and energy production in a power plant.
A nuclear power plant uses fission as an energy source by building larger atoms from smaller atoms.
A nuclear power plant uses fusion as an energy source by building larger atoms from smaller atoms.
A nuclear power plant uses fusion as an energy source by breaking apart atoms.
A star uses fusion as an energy source by building larger atoms from smaller atoms.
A star uses fusion as an energy source by building larger atoms from smaller atoms.
119
Which process produces the energy that fuels the Sun?
Three helium nuclei collide and fuse together to create carbon plus energy.
Two neutrons collide and fuse together to create hydrogen plus energy.
Carbon and hydrogen atoms collide and fuse together to create nitrogen, oxygen, then helium plus energy.
Hydrogen atoms collide and fuse together to create helium plus energy.
Hydrogen atoms collide and fuse together to create helium plus energy
120
Identify the primary roles of dust in the formation of the early Solar System.
forming Saturn's rings
acting as nuclei on which other particles attached
cooling warm material by radiating its heat away
warming material by absorbing heat from the Sun
increasing the rate at which the forming Sun rotates
acting as nuclei on which other particles attached and cooling warm material by radiating its heat away
121
Select the correct mechanism responsible for the formation of the Oort cloud and the Kuiper belt.
the formation of planetesimals in their current locations, far from the Sun
the ejection of planetesimals due to the explosive death of a star that preceded the Sun
the ejection of planetesimals due to their gravitational interaction with giant planets
the ejection of planetesimals due to radiation pressure from the Sun
the ejection of planetesimals due to their gravitational interaction with giant planets
122
Which of the properties of the Solar System are explained by the Grand Tack hypothesis?
Mars is much less massive than Earth
The runaway greenhouse effect on Venus.
Uranus and Neptune contain methane ice.
The planets are not ordered from smallest to largest with distance from the Sun.
The asteroid belt contains objects that originate from both the inner and outer Solar System.
Mars is much less massive than Earth and The asteroid belt contains objects that originate from both the inner and outer Solar System.
123
The outer planets in the Solar System are composed primarily of light elements, such as hydrogen and helium, whereas the inner planets are composed of heavier elements, such as silicon and iron. What is the reason for this difference?
the inner planets do not have the gravity to hold onto the lighter elements
the outer planets formed earlier and captured most of the light elements before the inner planets could
the young and forming Sun did not have the gravity to hold onto the lighter elements near it
the difference in the temperature between the inner and outer solar system
the difference in the temperature between the inner and outer solar system
124
Which statement does not describe a probable result of collisions in the early Solar System?
The inner planets gained ice-rich materials.
The Moon was formed.
Uranus gained its ice-rich composition.
Mercury was stripped of its mantle and crust.
Uranus gained its ice-rich composition.
125
The greenhouse effect
was created by human activity; it does not occur naturally on any planet.
occurs when atmospheric gases reflect infrared radiation, causing increased atmospheric cooling.
occurs when nitrogen and oxygen in Earth's atmosphere absorb infrared energy, slowing heat loss to space.
occurs when heat is trapped by a planet's atmosphere, making the planet warmer than it would be otherwise.
occurs when heat is trapped by a planet's atmosphere, making the planet warmer than it would be otherwise.
126
The ozone layer in the Earth's atmosphere protects the Earth's surface from
infrared radiation
cosmic rays.
gamma rays.
ultraviolet radiation
ultraviolet radiation
127
Approximately 80% of infrared (IR) radiation emitted by Earth is trapped by greenhouse gases, which causes the warming
of Earth's atmosphere known as the greenhouse effect. Even though nitrogen (N2,) and oxygen (O2,) make up approximately
99% of the atmosphere, they do not contribute to the greenhouse effect. However, carbon dioxide (CO2,) is a
major contributor.
Why does CO2, contribute to the greenhouse effect, whereas N2, and O2, do not?
All infrared radiation is absorbed in the lower atmosphere (troposphere), and does not reach the upper atmosphere
(stratosphere) where N2, and O2, exist.
CO2, absorbs ultraviolet radiation escaping from the Earth's surface, which creates a thermal barrier.
CO2, absorbs the majority of the ultraviolet radiation in the troposphere, which traps heat close to Earth's surface.
CO2, is capable of absorbing infrared radiation, whereas N2, and O2, are not.
CO2, is capable of absorbing infrared radiation, whereas N2, and O2, are not.
128
What is the main cause of global warming?
acid rain
an overall increase in Earth's temperature
the greenhouse effect
an increased concentration of CO2, and other greenhouse gases
an increased concentration of CO2, and other greenhouse gases
129
Which of these statements is true about plate tectonics?
Individual plates on Earth slowly drift and collide because the plates rotate around fixed axes.
Earth's rapid rotation and tidal forces from the Moon and Sun causes the continental plates to drift and collide.
The surface of the Earth consists of individual rigid crustal plates floating on the underlying semi-molten mantle.
The San Andreas Fault is part of the Mid-Atlantic Ridge where two crustal plates slide past each other, creating
significant and sizable earthquakes.
Two crustal plate boundaries can easily slide past each other because of the presence of seawater.
The surface of the Earth consists of individual rigid crustal plates floating on the underlying semi-molten mantle.
130
Which of the given are real tectonic plates on Earth today?
Pacific Plate
African Plate
South American Plate
Equatorial Plate
Pacific Plate
African Plate
South American Plate
131
Select the correct order of the layers of the Earth's interior, from the surface to the center.
core, mantle, troposphere
mantle, core, crust
core, mantle, crust
crust, mantle, core
crust, magnetosphere, core
crust, mantle, core
132
Select the correct order for the temperatures of the layers of the Earth, from the lowest temperature to the
highest temperature
core, mantle, troposphere
core, mantle, crust
mantle, core, crust
crust, mantle, core
crust, magnetosphere, core
crust, mantle, core
133
Select the correct statement that explains why Earth's inner core is solid and its outer core is liquid.
The inner core is much more dense than the outer core of Earth.
The temperature is much higher in the outer core than in the inner core of Earth.
The pressure is much higher in the inner core than in the outer core of Earth.
The outer core is composed of a different material than the inner core.
The pressure is much higher in the inner core than in the outer core of Earth.
134
What evidence exists to suggest that Earth was once molten and much hotter than it is today?
Earth has a strong magnetic field.
Volcanism continuously occurs on Earth.
Earth's interior is differentiated, with a core that is significantly hotter than its surface.
Most impact craters that were created in Earth's formation have eroded away.
Earth's interior is differentiated, with a core that is significantly hotter than its surface.
135
Choose the correct statement about aurorac.
Intense auroral displays created by high energy solar storms expose humans to dangerous levels of radiation.
The northern lights, or aurora borealis, and southern lights, or aurora australis, are most often seen near the Equator in
the tropics.
Aurorae on Earth are caused by charged particles from the Sun moving through Earth's magnetic field and striking the
upper atmosphere.
Aurorae are caused by high energy particles from the Sun interacting with the Van Allen belts and reflecting the
Sun's light.
Aurorae on Earth are caused by electrical currents in the ionosphere, generated by the dynamo action in Earth's core.
Aurorae on Earth are caused by charged particles from the Sun moving through Earth's magnetic field and striking the
upper atmosphere.
136
The surface of the Moon is covered by regolith, which is best described as
smooth, dark lava flows that cover some sections of the lunar highlands.
loose material composed of very small pieces of rock created by meteorite impacts and overlying the lunar bedrock.
deposits of sedimentary rocks left behind by small rivers and streams emanating from crater walls.
icy particles forming a thick, subsurface layer underneath the lunar soil and dust.
loose material composed of very small pieces of rock created by meteorite impacts and overlying the lunar bedrock.
137
According to the giant impact hypothesis, how did the Moon form?
A jovian planet was struck by a large asteroid and split into two smaller bodies, which became the Earth and the Moon.
The Moon was an asteroid that was captured by the Earth.
A Mars-sized object smashed into the molten proto-Earth, resulting in a larger Earth and debris that coalesced to form
the Moon.
A large iron asteroid collided with the rocky Earth during the late heavy bombardment. The asteroid carried material away from the Earth which accreted onto the asteroid and formed the Moon
A Mars-sized object smashed into the molten proto-Earth, resulting in a larger Earth and debris that coalesced to form the Moon.
138
Choose the correct statement which explains why the same side of the Moon always faces the Earth.
The period of the Moon's revolution is less than the period of its rotation.
The period of the Moon's rotation is equal to the period of its revolution.
The Moon rotates in the direction opposite the Earth's rotation, so the other side of the Moon is not seen during
one revolution.
The period of the Moon's rotation is less than the period of its revolution.
The period of the Moon's rotation is equal to the period of its revolution.
139
In the future, the Moon will be further from the Earth than it is today.
What will the lunar tides on Earth be like then compared to today?
The tides will be weaker.
The tides will be stronger.
The tides will not change.
The tides will be weaker.
140
What event do scientists think created the Caloris Basin on Mercury?
collision with a Mars-sized body
collision with an approximately 100 km wide body
extreme tectonic activity
melting from extreme solar activity while Mercury was forming
collision with an approximately 100 km wide body
141
Choose the statement that correctly describes the rotation and revolution of Mercury.
Mercury's rotational period is about 87 Earth days and its orbital period is about 58 Earth days. This is due to the
gravitational influence of Venus and Earth.
Mercury's rotational period lasts about 58 Earth days and its orbital period lasts about 87 Earth days. This is due to its
eccentric orbit and proximity to the Sun.
Mercury's rotational period is about 87 Earth days and its orbital period is 58 Earth days. This is due to its eccentric
orbit and proximity to the Sun.
Mercury's rotational period is about 58 Earth days and its orbital period is about 87 Earth days. This is due to the
gravitational influence of Venus and Earth.
Mercury's rotational period lasts about 58 Earth days and its orbital period lasts about 87 Earth days. This is due to its
eccentric orbit and proximity to the Sun.
142
Venus is sometimes called the morning star because
its thick atmosphere makes it appear to always be morning or evening on its surface.
The Roman goddess Venus was associated with the morning.
due to its proximity to the Sun it can only be seen just after sunset during western elongation.
it is so bright it makes the sky look like early morning.
due to its proximity to the Sun it can only be seen just after sunset during western elongation.
143
One of your friends wants to observe Venus with binoculars and plans a trip to a dark location at midnight in the winter.
You should tell your friend to
not bother. Venus is only visible during the day.
be sure to bring extra powerful binoculars because Venus is very faint and hard to find.
stay home. Venus is never visible at midnight.
have a good time!
stay home because Venus is only visible in the summer.
stay home. Venus is never visible at midnight.
144
Venus had a runaway greenhouse effect, but Earth does not because
Venus lacks water to pull the carbon dioxide out of its atmosphere.
Venus' volcanoes eject massive amounts of heat into the atmosphere.
Venus' retrograde rotation caused the carbon cycle to reverse.
Venus has a very transparent atmosphere which allows more of the Sun's light to reach the ground.
Venus lacks water to pull the carbon dioxide out of its atmosphere.
145
The surface of Venus is permanently covered by a thick layer of clouds, so astronomers have studied the surface by
radar from spacecraft that have landed on Venus' largest moon.
visible light observations from orbiting spacecraft.
manned missions to the surface.
images sent back by spacecraft that have landed on the surface.
images sent back by spacecraft that have landed on the surface.
146
Which of the given surface features are evidence that volcanic processes occurred on Venus? Mark all that apply.
large, circular coronae
impact craters
subduction zones
dome volcanoes
extensive lava flows
large, circular coronae
dome volcanoes
extensive lava flows
147
Select the true statements about the exploration of Venus. (multiple)
A lander built to survive for an extended period of time on the surface of Venus would need to be built to withstand
enormous pressure, like a submersible 900 meters below the surface of Earth's oceans.
The United States was the first nation to land a probe on the surface of Venus with NASA's Pioneer Venus 2 mission.
which touched down in 1978
Landers on Venus have been able to study the planet's seasons by operating for an entire Venus year.
Using radar imaging. NASA's Magellan orbiter created a topographical map of nearly the entire surface of Venus.
A lander built to survive for an extended period of time on the surface of Venus would need to be built to withstand
enormous pressure, like a submersible 900 meters below the surface of Earth's oceans.
Using radar imaging. NASA's Magellan orbiter created a topographical map of nearly the entire surface of Venus.
148
Compared to the other planets, what features of the
rotation of Venus are unusual? Choose all that apply.
Venus rotates clockwise as viewed from a point far
above the Sun's North Pole.
Venus rotates at the fastest rate.
Venus rotates at the slowest rate.
Venus rotates counterclockwise as viewed from a point far above the Sun's North Pole.
Venus' rotation axis is nearly in its orbital plane.
Venus rotates clockwise as viewed from a point far
above the Sun's North Pole.
Venus rotates at the slowest rate.
149
The thickness of a terrestrial planet's atmosphere is determined primarily by
its brightness and temperature.
its mass and the number of its moons.
its mass, temperature, and amount of geological activity.
its mass and brightness.
its mass, temperature, and amount of geological activity.
150
Which of the planets and moons could be closest to the Sun and still retain a nitrogen atmosphere?
Ganymede, a moon of Jupiter
Mars
Earth
Earth's moon
Earth
151
Identify the pieces of evidence that indicate that liquid water once existed on Mars.
Martian gullies carved into hill slopes and channel walls appear to have formed by flows of water.
Martian rocks contain jarosite minerals believed to have formed in the presence of water.
Ice and debris flows appear to be cascading down the slopes of Mars' active volcanoes.
Fan-shaped deposits of sediment emerge from upland areas into broad valleys and plains.
Martian gullies carved into hill slopes and channel walls appear to have formed by flows of water.
Martian rocks contain jarosite minerals believed to have formed in the presence of water
Fan-shaped deposits of sediment emerge from upland areas into broad valleys and plains.
152
Mars appears red because
chemical reactions in its dense atmosphere result in reddish-orange clouds.
there is plentiful dust rich in iron covering its surface.
light from Mars is highly redshifted as it orbits the Sun.
the surface of Mars is dominated by the centuries-old Great Red Spot.
Earth's atmosphere scatters the shorter wavelength blue light, leaving just the red light to get through to an observer.
there is plentiful dust rich in iron covering its surface.
153
Volcanoes on Mars are enormous because
the lack of plate tectonics means that volcanoes stay over a "hot spot" for billions of years.
Mars is the most geologically active planet in the Solar System.
tidal forces from Phobos and Deimos have weakened Mars' crust, allowing volcanoes to grow bigger.
there is very little atmosphere to erode them away.
the lack of plate tectonics means that volcanoes stay over a "hot spot" for billions of years.
154
Photographs obtained by the NASA probe Mariner 9 revealed a vast canyon on Mars that has since been named
Valles Marineris.
Select the true statements concerning the Valles Marineris.
It was created by an asteroid impact.
Its widest point is wider than the diameter of Meteor Crater in Arizona.
It is a fracture in the crust.
It is longer than the distance between Los Angeles and San Francisco.
It encircles two-thirds of the entire planet.
Its widest point is wider than the diameter of Meteor Crater in Arizona.
It is a fracture in the crust.
It is longer than the distance between Los Angeles and San Francisco.
155
Identify the processes that lead to the zonal bands on
Jupiter's visible surface.
ammonia sublimation
convection
volcanism
Jupiter's rapid rotation
friction
convection
Jupiter's rapid rotation
156
Choose the correct order of the Galilean moons from
largest to smallest.
Europa, Callisto, Ganymede, lo
Ganymede, Callisto, Io, Europa
Europa, lo, Callisto, Ganymede
lo, Europa, Ganymede, Callisto
Ganymede, Callisto, Io, Europa
157
Which moon, therefore, has the geologically youngest surface?
Callisto
Ganymede
Europa
lo
lo
158
Which number is closest to how many moons astronomers have identified orbiting Jupiter?
20
1
120
80
80
159
Compared to the inner, prograde satellites, some of Jupiter's outer satellites move in retrograde orbits, i.e., their orbital direction is opposite to the rotation of Jupiter. What could explain the retrograde motion of these satellites?
Collisions between Jupiters satellites changed their orbits.
These satellites were captured by Jupiter from solar orbits.
Their retrograde orbit is an apparent motion due to the different orbital speeds of Earth and Jupiter
These satellites formed in orbit of Jupiter with retrograde orbits.
These satellites were captured by Jupiter from solar orbits.
160
Jupiter has almost twice the average density of Saturn because
Saturn has a lower average temperature than Jupiter.
Jupiter has a much larger radius than Saturn.
Saturn has a higher proportion of hydrogen.
Jupiter has a much stronger gravitational force than Saturn.
Jupiter has a much stronger gravitational force than Saturn.
161
Compared to Saturn, the cloud layers in Jupiter's atmosphere are proportionally
about the same thickness.
thinner.
thicker.
thinner.
162
Saturn's internal heat source is connected to
nuclear reactions fusing hydrogen into helium.
liquid helium precipitation in its atmosphere.
tidal stresses from nearby Jupiter and its many moons.
leftover heat from when the planet was originally formed.
liquid helium precipitation in its atmosphere.
163
Saturn's rings are sometimes easy to observe and sometimes almost disappear because
the physical size of Saturn's rings changes seasonally, depending on how its hemispheres are tilted toward and away
from the Sun.
the rings are extremely thin and tilted relative to Saturn's orbital plane.
ring systems are not permanent and can be disrupted and replenished by many different processes.
they are regularly eclipsed by Saturn's dozens of moons, which can block an observer's view of the bright rings.
the rings are extremely thin and tilted relative to Saturn's orbital plane.
164
Planetary ring systems can result from the destruction of a moon orbiting within the Roche limit of a planet.
Choose the statement that best describes how a moon can be destroyed within this limit.
The planet's magnetic field rips the moon apart.
Drag from the atmosphere causes the moon to break up.
The chance of collision with other objects increases.
Tidal forces exceed the forces holding the moon together.
Tidal forces exceed the forces holding the moon together.
165
Why does Saturn's moon Titan have such a dense atmosphere compared to other moons in the Solar System?
The Sun heats the atmosphere, making it more dense and permanent.
Actually, Titan's atmosphere is typical of most moons in the Solar System.
Titan is much more massive than moons like Callisto and Ganymede, allowing it to retain its atmosphere because of its
stronger gravity
It has been able to retain its atmosphere because it is so far from the Sun.
It has been able to retain its atmosphere because it is so far from the Sun.
166
What keeps the water in cryovolcanoes on moons like Enceladus from being frozen solid?
Tidal forces stretch, squeeze, and heat the moon's interior as the moon orbits the planet.
The moon orbits a planet, which radiates enough heat to warm the moon's surface.
Energy from the Sun melts ice near the moon's surface.
Heat generated by accretion early in the moon's history keeps the interior molten.
Tidal forces stretch, squeeze, and heat the moon's interior as the moon orbits the planet.
167
What would seasons be like on Uranus at a location close to the south pole?
The seasons would be the same as seasons in Earth's polar regions, except the average temperature would be much
cooler due to Uranus' greater distance from the Sun.
Because Uranus rotates on its side as it orbits, the southern hemisphere always faces the Sun and experiences summer.
The other hemisphere is always dark and experiences winter.
There are no seasons on Uranus because it orbits too far from the Sun.
The seasons would be more extreme than for any location on Earth, with periods of constant darkness and light that last several Earth decades each
The seasons would be more extreme than for any location on Earth, with periods of constant darkness and light that last several Earth decades each
168
Miranda is a moon of the planet
Neptune
Mars.
Jupiter
Uranus.
Saturn.
Uranus.
169
Miranda's surface shows signs of
volcanic calderas and vents
extensive cratering, more than any other object in the Solar System.
sedimentary layers.
fault canyons, grooves, and other jumbled, uneven terrain.
fault canyons, grooves, and other jumbled, uneven terrain.
170
Miranda's surface features are most likely due to
a catastrophic past
flowing water in its past.
active volcanism.
a catastrophic past
171
Consider a hypothetical moon orbiting a planet in the Solar System; this moon orbits within the planet's equatorial plane in a prograde orbit and is spherical. This moon most likely
formed at the same time as its planet.
was captured after the planet was finished forming.
formed at the same time as its planet.
172
Why are the predominant colors of Uranus and Neptune different from those of Jupiter and Saturn?
Methane in the atmospheres of Uranus and Neptune absorbs the longer wavelengths of visible light.
Methane in the atmospheres of Uranus and Neptune has a bright emission line in the blue part of the spectrum.
The surfaces of Neptune and Uranus are mostly covered with liquid water and appear blue from reflected light.
Uranus and Neptune, which are much warmer than Jupiter and Saturn, emit more blue light.
Methane in the atmospheres of Uranus and Neptune absorbs the longer wavelengths of visible light.
173
Choose the correct statement or statements about the asteroid belt.
The main asteroid belt is a region between the orbits of Mars and Jupiter lying between about 2.1 and 4.1 AU from
the Sun.
The main asteroid belt environment is an active and chaotic part of the Solar System where frequent collisions occur
between rocky masses.
The main asteroid belt is a region between the orbits of Earth and Mars Iying between about 1 and 2.1 AU from
the Sun…
Most asteroids are larger than the Earth.
A collision between a comet and planet created the main asteroid belt between Mars and Jupiter.
The main asteroid belt is a region between the orbits of Mars and Jupiter lying between about 2.1 and 4.1 AU from
the Sun.
174
The combined mass of the asteroid belt is
less than the mass of Saturn but greater than the mass of Uranus.
smaller than the Earth's mass, but larger than the mass of Mars.
larger than the mass of Jupiter.
less than the mass of Mars.
less than the mass of Mars.
175
At certain distances from the Sun, asteroids in the main asteroid belt are in an orbital resonance with Jupiter, creating gaps in the belt called Kirkwood gaps. Jupiter orbits the Sun with a period of 11.9 years. Which of the following is not a period of an asteroid that is in an orbital resonance with Jupiter?
4.76 years
5.95 years
4.38 years
3.97 years
4.38 years
176
A typical asteroid in the asteroid belt is closest to the size of
the planet Mercury.
a building.
the United States.
the state of Montana.
a building.
177
What are Trojan asteroids?
Trojan asteroids are asteroids on a trajectory which will intercept Earth.
Trojan asteroids are asteroids in the asteroid belt which are the remnants of the planet Troy.
Trojan asteroids are objects which share the orbit of Jupiter.
Trojan asteroids are objects which share the orbit of Earth.
Trojan asteroids are objects which share the orbit of Jupiter.
178
A comet develops two tails of different composition as it approaches the Sun. What are the two tails primarily
composed of?
rocks and photons
dust and gas
photons and gas
ice and rocks
ice and dust
dust and gas
179
How do the two different comet tails behave as the comet approaches the Sun?
The lighter tail is pushed directly away from the Sun, whereas the heavier tail trails behind curved toward the path of the comet.
The heavier tail becomes fainter as more heavy particles are added and the lighter tail becomes brighter as it is ionized
by the Sun.
The heavier tail becomes longer as more material is released from the comet, whereas the lighter tail becomes smaller
as its material slowly escapes.
The lighter tail evaporates from the heat of the Sun and the heavier tail becomes energized and brightens the
comet significantly
180
When several meteors are observed to radiate in the night sky the event is called a meteor shower. This often occurs at
predictable times throughout the year when
an asteroid explodes into many small pieces in Earth's atmosphere.
Earth travels through a stream of icy, dusty debris left behind by a comet.
the solar wind pushes a comet into Earth's orbit.
Earth passes through our Solar System's main asteroid belt.
Earth travels through a stream of icy, dusty debris left behind by a comet.
