astronomy test 2
what was the most probable order of events for the collision that led to the formation of the Moon?Rank the steps of the impact theory from earliest to latest
1)Iron core of Earth forms. 2)Mars-sized object collides with Earth. 3)If the Mars-sized object has an iron core, most or all of it is left behind on Earth and merges with Earth's core. 4)The Moon forms out of rocky debris ejected from Earth during the collision.
The following steps describe the process of events leading to the formation of an aurora. Rank the steps in sequence from first to last, in order of how they must occur.
1)Solar wind encounters Earth's magnetosphere. 2)Charged particles become trapped inVan Allen belts. 3)Charged particles collide with atoms in Earth's upper atmosphere. 4)The collisions transfer energy and excite the atmospheric atoms 5)Excited, atmospheric atoms fall back to their ground state. 6)Auroral lights are observed on Earth.
predictions of impact theory
Computer simulations would need to predict that a collision between Earth and a Mars-sized object would produce a Moon-sized satellite with a stable orbit. The Moon and Earth should have similar mantle compositions, but other parts of their compositions should be dissimilar.
predictions of the Capture theory
The Moon and Earth should have completely different compositions. Mathematical models would need to predict that the capture of a Moon-sized satellite would be likely in Earth's early history.
prediction of Coformation theory
The Moon and Earth should have very similar compositions.
After two half-lives have passed, the ratio of a radioactive element to its daughter element is
a)1 to 1. b)0 to 4. c)1 to 3. d)1 to 4. e)1 to 2. answer:c
If an unstable element in a sample decays for 4 half-lives, about how much of the unstable element is left?
a)1/8 b)1/16 c)1/2 d)1/4 answer:b
Venus orbits the Sun in 225 days. How long does it take to rotate on its axis?
a)36 days, for reasons unknown b)24 hours, 36 minutes, very similar to Earth and Mars c)450 days, exactly at 2:1 spin-orbit resonance d)225 days, so it keeps the same face toward the Sun e)243 days, even though the Earth's tidal pull is not involved answer:e
Suppose three planets all have similar rocky surfaces but different average densities as in the choices below. Which planet is likely to have a large iron core?
a)6000 kg/m3 b)3000 kg/m3 c)4500 kg/m3 answer:a
What is the percentage of Earth's atmosphere (by volume) that is carbon dioxide (CO2)?
a)78 b)0.9 c)3 d)0.03 e)21 answer:d
How is the existence of Earth's unique atmosphere explained?
a)As Earth cooled, water vapor fell out of the atmosphere to form the oceans. b)When Earth formed, its atmosphere formed from the gases most common in the early solar system. c)Ultraviolet radiation from the Sun freed the hydrogen, allowing it to escape. d)Volcanic gases containing nitrogen were outgassed from Earth's interior. e)The oxygen in Earth's atmosphere is a result of early life on Earth. answer:e
Earth is the only terrestrial planet with a large, spherical Moon. Many theories have been proposed to explain this somewhat unusual Earth-Moon system. Which of the following are NOT theories proposed to explain the Moon's formation?
a)Capture b)Impact c)Co-formation d)Spin-off answer:d
What are the major factors that rule out the co-formation theory for the Moon-Earth system?
a)Each body has different atmospheric content and a different density. b)Each body has a different density and a different chemical composition. c)Each body has different chemical composition and different surface features. d)Each body has a different chemical composition and different atmospheric content. e)Each body has different surface features and different atmospheric content. answer:b
Which terrestrial planet would have its surface temperature the most dramatically changed if its greenhouse gases were removed from its atmosphere?
a)Earth b)Mars c)Mercury d)Venus answer:d
Comparing what you know about the predictions of each Moon formation theory, determine which of the following observations and experiments have been verified.
a)Earth has a large iron core; the Moon does not. b)Both Earth and the Moon have large iron cores. c)The mantles of Earth and the Moon have similar compositions. d)The mantles of Earth and the Moon have completely different compositions. e)Mathematical models predict that capture of a Moon-sized satellite would be very likely in Earth's early history. f)Computer simulations predict that a collision between Earth and a Mars-sized object would produce a Moon-sized satellite with a stable orbit. answers:a,c,f
Without the Greenhouse Effect operating in our atmosphere,
a)Earth would have an average temperature of -23 degrees Celsius. b)the ozone layer would not be weakening. c)the Earth would have become much more like Venus long ago. d)we would not have to worry about any warming problems in the future. e)the ice in the polar regions would have melted long ago. answer:a
Our most detailed maps of Venus come from:
a)Earth-based radio telescopes. b)the Hubble Space Telescope. c)the Magellan space probe. d)direct observation from Earth-based optical telescopes. e)manned landings. answer:c
Which of these theories seems to best explain the Moon's origin?
a)Fusion Theory b)Impact Theory c)Fission Theory d)Coformation Theory e)Capture Theory answer:b
What impact has the greenhouse effect had on the surface environment of Venus?
a)It has had little or no impact. b)It has produced about the same impact as on Earth. c)It has reduced the surface temperature by about 30 degrees. d)It has raised the surface temperature by hundreds of degrees. answer:d
What causes Mercury's 3:2 spin-orbit resonance?
a)the planet's closeness to the Sun b)the planet's very eccentric orbit c)the planet's high density d)tidal torques operating on the planet e)All of the above are factors. answer:e
On a cloudless day, what happens to most of the visible light headed toward Earth?
a)It is reflected by Earth's atmosphere. b)It is absorbed and reemitted by gases in Earth's atmosphere. c)It is completely reflected by Earth's surface. d)It reaches Earth's surface, where some is reflected and some is absorbed. Submit answer:d
What happens to the energy that the ground absorbs in the form of visible sunlight?
a)It is returned upward in the form of infrared light. b)It is returned upward in the form of visible light. c)It makes the ground continually get hotter and hotter. Submit answer:a
What is the result of the greenhouse effect on the surface environment of Venus?
a)Its effect is about the same as on Earth. b)It causes the surface temperature of Venus to become hotter than the Sun. c)It has reduced the surface temperature by about 30 degrees Celsius. d)It has raised the surface temperature by hundreds of degrees Celsius. e)It has little or no effect. answer:d
Mercury and the Moon appear similar, but we note that:
a)Mercury does not always keep the same face toward the Sun, while the Moon does have the Earthside always facing us. b)Mercury has striking scarps due to the shrinking of its core. c)the lunar mare are darker than Mercury's intercrater plains. d)Mercury has "weird terrain" opposite its huge Caloris Basin. e)All of the above are correct. answer:e
According to the current understanding of Earth's magnetic field and how magnetic fields are generated, which two components in Earth's internal structure are required in order to generate a magnetic field?
a)Rapidly rotating core b)Conducting liquid core c)Completely solid interior d)Solid iron poles e)Plate tectonics Submit answers: a & b
How do the densities of the jovian and terrestrial planets compare?
a)The closer a planet lies to the Sun, the less its density. b)More massive jovians all have high densities, compared to the tiny terrestrials. c)No real pattern here; densities vary greatly and are very individual to each world. d)All terrestrials are denser than any of the jovians. e)Made from the same solar nebula, they are all similar. answer:d
Which of the following statements about the atmosphere of Venus and its contents is NOT true?
a)The clouds in the atmosphere of Venus are composed primarily of sulfuric acid. b)The coldest layers of Venus's atmosphere are 50 to 150 km above its surface. c)There is no significant ozone layer in the atmosphere of Venus. d)The clouds of Venus are made of highly reflective frozen carbon dioxide. e)The atmosphere of Venus is composed primarily of carbon dioxide. answer:d
On a day with complete cloud cover, what happens to the visible light headed toward Earth?
a)The clouds reflect much of it back to space, though some still reaches the surface. b)It is absorbed by the clouds, which causes the clouds to heat up. c)It reaches the surface just as it does on a cloudless day. Submit answer:a
Which of the following statements about global warming is NOT true?
a)The global mean temperature in the modern era is the highest is has ever been. b)Rises in global mean temperature tend to be closely associated with rises in atmospheric carbon dioxide concentrations. c)Computer models indicate that only human contributions to atmospheric carbon dioxide can account for recent global temperature rises. d)Atmospheric carbon dioxide levels have risen dramatically over the past hundred years or so. Submit answer:a
Why are there more craters in the lunar highlands than in the maria?
a)The maria are more heavily eroded. b)The highlands are higher in elevation and thus attract more impactors. c)The highlands are older than the maria. d)The maria are older than the highlands. answer:c
Why is the sky blue?
a)The oceans refract the light from the Sun into the atmosphere. b)The atmosphere scatters the light from the Sun. c)The atmosphere reflects the light from the Sun. d)The oceans reflect the light from the Sun into the atmosphere. e)The atmosphere reflects the color of the oceans. answer:b
If Venus once had an ocean, where did it go?
a)The water broke into hydrogen, which escaped to space, and oxygen, which became trapped in the planet's surface rocks. b)It exists trapped in the crust but below the surface. c)It is found in the cooler polar regions, like at the Moon and Mercury. d)It was lost to space, stripped away by the solar wind. e)It exists as abundant water vapor in the planet's atmosphere. answer:a
What is true of the Moon's orbital and rotational periods?
a)They are equal. b)The rotational period is longer. c)The orbital period is longer. d)The rotational period varies with the Moon's phase. e)The orbital period is greatest at full moon. answer:a
Why is it reasonable to conclude that the internal structure and evolution of Venus are basically Earthlike?
a)They have similar masses and sizes. b)
Why is it reasonable to conclude that the internal structure and evolution of Venus are basically Earthlike?
a)They have similar masses and sizes. b)They have similar surface features and sizes. c)They have similar chemical compositions and surface features. d)They have similar atmospheres and masses. e)They have similar atmospheres and chemical compositions. answer:a
Why does Venus appear so bright to the eye?
a)Venus is closer to the Sun, so gets more intense sunlight. b)The planet's cloud-cover is highly reflective, reflecting 60% of the Sun's light. c)It gets closer to us than any other planet does. d)As seen from Earth, the disk of Venus can appear larger than any other planet's. e)All of the above are correct. answer:e
Scientists expected Venus to have a large amount of water. However, little detectable water has been found anywhere on Venus, either on its surface or in its atmosphere. Water, like carbon dioxide, is a greenhouse gas. What is NOT a reason for Venus to now be so dry?
a)Water originally in Venus's atmosphere intensified the greenhouse effect, heating the atmosphere. b)Venus's superheated atmosphere and solar ultraviolet radiation broke water into hydrogen and oxygen. The hydrogen gas escaped while the oxygen combined with other atmospheric gasses. c)Venus never had any water because it is too close to the Sun. answer:c
Which of the following is NOT involved in the production of Earth's magnetic field?
a)a composition high in conducting metals b)rotation of the core c)oceans d)a differentiated structure answer:c
Venus's temperature is fairly uniform over the entire planet, both day and night.
true false answer:true
Compared to Earth, Venus has:
a)a far greater percentage of its surface in raised continents. b)a far greater percentage of its surface in low-level ocean basins. c)a more transparent atmosphere. d)about the same percentage of its surface in raised continents. e)a lower average surface temperature. answer:b
To measure how Mercury spins, astronomers sent ________ to Mercury and used the Doppler shift to determine how fast it was rotating.
a)a single frequency radio signal b)probes c)a satellite d)radar beams e)laser beams answer:d
The scarps on Mercury were probably caused by:
a)a tidal bulge. b)volcanism c)the interior cooling and shrinking. d)tectonic activity. e)meteorite bombardment. answer:c
If you were making a scale model of Earth representing our planet by a 12-inch basketball, the inner core would be about the size of
a)a ½-inch ball bearing. b)2-inch golf ball. c)4-inch tangerine. d)7-inch grapefruit. answer:b
Earth and Venus are often called sister planets; in which ways are they most alike?
a)atmospheric composition and density b)polar caps and rusty red deserts c)surface temperature and pressure d)size, density, and surface gravity e)cloud composition and meteorology answer:d
Which of the following is NOT a factor in determining whether a body in the solar system retains an atmosphere?
a)axial tilt b)rotation rate c)composition and weight of the gases d)escape velocity e)distance from the Sun answer:b
The cores of the Moon and Mercury are similar in that
a)both cores are more iron rich than the rest of the body and the core is solid throughout. b)both cores are large in proportion to the object with a solid inner core and fluid outer core. c)both cores are more iron rich than the rest of the body, with a solid inner core and fluid outer core. d)both cores are small in proportion to the object, with a fluid inner core and solid outer core. answer:c
What gas is the primary constituent of our atmosphere?
a)carbon dioxide b)nitrogen c)oxygen d)helium e)hydrogen answer:b
What is the main constituent of the atmosphere of Venus?
a)carbon dioxide b)sulfuric acid c)hydrogen d)nitrogen e)oxygen answer:a
Which of these gases are outgassed from our volcanic eruptions?
a)carbon dioxide, water vapor, oxygen b)ammonia, water vapor, oxygen c)water vapor, methane, carbon dioxide d)helium, carbon dioxide, methane e)oxygen, methane, ammonia answer:c
What is the primary cause of the aurorae (Northern and Southern lights)?
a)cold air trapped over poles b)charged particles interacting with the atmosphere c)reflections from polar ice d)diffraction in the atmosphere e)drift of pollutants to the poles answer:b
Which property of Venus's atmosphere gave rise to the runaway greenhouse effect?
a)composition of the atmospheric gases b)thickness c)composition of the clouds d)high temperature answer:a
Which of the following characteristics describes the conditions that prevail on the surface of Venus?
a)cool, moist, and humid b)cool, dry, and windy c)hot, dry, and dusty d)hot, moist, and humid e)hot, windy, and dry answer:c
Which of the following layers of the Earth is unique among the terrestrial planets?
a)core b)ionosphere c)mantle d)crust e)hydrosphere answer:e
Increasing the concentration of greenhouse gases in Earth's atmosphere
a)decreases the transparency of the atmosphere to infrared light. b)increases the transparency of the atmosphere to infrared light. c)decreases the transparency of the atmosphere to visible light. d)increases the transparency of the atmosphere to visible light. answer:a
What is the cause of tectonic plate motion?
a)earthquakes b)tidal forces from the Moon c)convection in the upper mantle d)magnetic field reversals e)Earth's rotation answer:c
The most likely theory of the formation of Earth's Moon is that it
a)formed from a collision of Earth with a Mars-sized object. b)formed simultaneously with Earth's formation. c)was created from a collision scooping out the Pacific Ocean. d)was formed by the gravitational capture of a large asteroid. answer:a
Earth's average density is about the same as that of
a)glass of water. b)heavy iron meteorite. c)chunk of black volcanic rock. d)ice cube. answer:c
In relation to the density of Earth's Moon, Mercury's density suggests that the planet
a)has a stronger magnetic field than the Moon. b)has a dense metal core. c)is younger than the Moon. d)has an interior structure similar to that of the Moon. answer:b
Venus's permanent retrograde rotation about its axis results in the planet
a)having its north pole below the plane of the ecliptic. b)always rising in the western sky. c)orbiting the Sun in the opposite direction from Earth. d)being brighter than any other planet. answer:a
Mercury is very hard to observe from Earth because:
a)it always appears as only half lit from Earth. b)its elliptical orbit causes it to change speed unpredictably. c)it never gets more than 28 degrees from the Sun's glare. d)its barren surface reflects too little sunlight; it is almost invisible always. e)its very rugged surface does not allow radar to bounce back to Earth. answer:c
Venus is never seen at midnight because
a)it will be at superior conjunction. b)it is visible only at sunset. c)it will be in its new phase then. d)it is closer to the Sun than is Earth. answer:d
Venus is the hottest planet chiefly because:
a)it's the closest planet to the Sun. b)of the carbon dioxide in its atmosphere. c)of the volcanic activity on the surface. d)of the oxygen in the atmosphere. answer:b
The lack of any significant magnetic field on Venus probably is due in part to which of the following characteristics?
a)its solid core b)its high surface temperature c)its nearness to the Sun d)its thick atmosphere e)its slow overall rotation answer:e
Radioactive decay of heavy elements typically involves the emission of:
a)lead b)uranium. c)helium nuclei. Submit answer:c
Greenhouse gases in our atmosphere trap just enough heat to keep the Earth's oceans liquid.
true false answer:true
From the center outward, the correct order is:
a)molten metal hydrosphere, molten rock lithosphere, solid silicate crust. b)solid rock core, liquid metal mantle, solid rock crust. c)liquid iron inner core, solid nickel outer core, rocky mantle, silicate crust. d)solid metallic inner core, molten metal outer core, silicate mantle and crust. e)solid metal core, molten metal hydrosphere, rocky lithosphere, gases in atmosphere. Submit answer:d
Mercury's surface most resembles that of which other body?
a)moon b)lo c)Earth d)Venus e)Mars answer:a
Venus is only a little bit (5%) smaller than Earth, and its density is only slightly less than Earth's. Therefore, its mass is:
a)much greater than Earth's (more than 20% different). b)the same as Earth's. c)much less than Earth's (more than 20% different). d)just a little bit greater than Earth's. e)just a little bit less than Earth's. answer:e
Compared with Earth, Venus has a level of plate tectonic activity that is
a)much more rapid. b)virtually nonexistent. c)about the same. answer:b
The absence of a magnetic field on Venus probably stems from its:
a)nearness to the Sun. b)slow rotation. c)lower density than Earth, suggesting an absence of an iron core. d)extremely thick atmosphere. e)high surface temperatures. answer:b
The Moon is locked in synchronous orbit with Earth. How many times does the Moon rotate every time it completes one revolution?
a)one b)two and a half c)two d)one and a half answer:a
Through radar observations it was found that Venus's:
a)orbit around the Sun is speeding up. b)orbit around the Sun is in the clockwise sense. c)atmosphere is changing rapidly. d)orbital period is 243 days. e)rotation on its axis is retrograde. answer:e
The critical part of the atmosphere for protecting life on the ground from excessive ultraviolet radiation is the:
a)ozone layer b)stratosphere c)troposphere d)hydrosphere e)ionosphere answer:a
If there were significantly more greenhouse gases, such as CO2, in Earth's atmosphere, then
a)plants would grow faster than animals could eat them. b)the ozone hole would get larger. c)the ozone hole would close. d)Earth's average temperature would change. answer:d
Because of its slow rotation period, Venus:
a)presents the same side to Earth all the time. b)gets closer to Earth than any other planet. c)presents the same side to the Sun all the time. d)presents the same side to Earth at each closest approach. e)appears to go through phases like the Moon. answer:d
Our best data about the surface topography of Venus has come from:
a)radio and visual observations. b)orbiter photos from Pioneer Venus Orbiter. c)the three flybys of Mariner 10. d)spacecraft flybys like Mariner 2 and visual observations of the planet. e)Magellan radar data and radar observations of the planet from Earth. answer:e
The atmospheric pressure on Venus:
a)shows an extreme change with the seasons. b)is much higher than on Earth. c)is about the same as on Mercury. d)is much lower than on Earth. e)causes variations in surface temperature. answer:b
Which of the following best describes Venus's rotation?
a)slow and retrograde b)fast and retrograde c)fast and prograde d)slow and prograde answer:a
Venus's surface is permanently obscured by clouds. As a result, the surface has been studied primarily by
a)spectroscopy. b)orbiting satellites using radar. c)robotic landers . d)radar signals from Earth. answer:b
The principal greenhouse gases in our present atmosphere are:
a)sulfuric acid vapor and carbon dioxide. b)hydrogen sulfide and carbon disulfide. c)water vapor and carbon dioxide. d)methane and ammonia. e)hydrogen and helium. answer:c
Venus's rotation:
a)takes longer than its orbit around the Sun. b)axis is highly tilted to its orbital plane, causing large seasonal changes. c)is the fastest of the terrestrial planets. d)is tidally locked to the Sun. e)is counterclockwise, like the other planets. answer:a
Comparing the densities of the Moon and Mercury, we find:
a)that density increases as we go outward from the Sun. b)both are much denser than our water-covered planet. c)similar in surface appearance, they are also similar in density. d)the Moon's is similar to Earth's crust, while Mercury's is similar to the entire Earth. e)the Moon is slightly denser than Mercury. answer:d
In noting that our world is "differentiated," we mean that:
a)the density of its materials decreases as you go downward toward the core. b)the Earth's magnetic field is different now in polarity than it was 700,000 years ago. c)radioactive heating in the core is at a slower pace than when the Earth was new. d)the iron and nickel core is denser than the silicate mantle and crust. e)the Earth has evolved in a different pattern than any other planet. answer:d
Seismic waves are most useful for mapping:
a)the depths of the oceans. b)the density of the hydrosphere. c)the surface of Mars with Global Surveyor. d)the Earth's core and mantle. e)the surface of Venus with Magellan. answer:d
The Greenhouse Effect works by trapping:
a)the heat from the Sun in Earth's atmosphere. b)outgoing infrared radiation from the Earth. c)incoming infrared radiation from the Sun. d)outgoing ultraviolet radiation from the Earth. e)incoming ultraviolet radiation from the Sun. answer:b
The reason that the atmosphere of Venus is over 95% carbon dioxide is thought to be because:
a)the part of the solar nebula where Venus formed contained more carbon dioxide than the part where Earth formed. b)the early plant life on Venus produced the excess carbon dioxide and consumed the oxygen. c)Venus was much hotter than Earth when its atmosphere formed. d)Venus's greenhouse effect got out of control and became runaway after its oceans of sulfuric acid evaporated. e)life on Earth formed earlier than on Venus. answer:c
The relative size of the atmosphere layer as compared to the solid part of Earth is most similar to:
a)the peel of an orange as compared to the meat of the orange. b)the meat of a peach as compared to the pit of the peach. c)the rind of a watermelon as compared to the meat of the watermelon. d)the skin of a grape as compared to the meat of the grape. e)the meat of a cherry as compared to the pit of the cherry. Submit answer:d
Volcanic activity on Venus is thought to be:
a)the same as volcanic activity on Earth. b)more frequent and more violent than volcanic activity on Earth. c)more frequent, but less violent than volcanic activity on Earth. d)less frequent, but more violent than volcanic activity on Earth. e)less frequent and less violent than volcanic activity on Earth. answer:d
The relatively small number of impact craters and the near absence of small craters on the surface of Venus are thought to be a result of:
a)the soft and resilient nature of the Venusian surface. b)the thick Venusian atmosphere. c)Venus' lack of a satellite. d)the position of Venus in the solar system-not many meteoroids cross Venus' orbit. e)the ancient oceans that once existed on Venus. answer:a
Planets and moons showing the most craters have
a)the strongest gravity. b)the oldest surfaces. c)been hit by meteors the most times. d)molten cores. answer:b
The main problem spacecraft have encountered in landing on Venus is:
a)the thick atmosphere. b)the extremely high temperatures. c)the strong winds. d)the acid rain. e)the rocky surface. answer:b
A heavily cratered surface probably means that:
a)there hasn't been any geological activity for billions of years. b)the core is likely made of iron. c)there has been a lot of recent geological activity. answer:a
When two tectonic plates collide:
a)they both stop moving. b)they continue moving, producing a variety of large deformations. c)volcanoes always mark the boundary between them. d)that region is safe from earthquakes now the plates are fixed. e)they always produce high mountain chains like the Himalayas. answer:b
The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface __________.
a)travels directly out to space b)becomes permanently trapped by greenhouse gases c)is temporarily absorbed by greenhouse gases and then reemitted in random directions Submit answer:c
Shield volcanoes on Venus are similar to what features on Earth?
a)volcanoes on moving plate boundaries b)There is no corresponding analog on Earth for Venus's shield volcanoes. c)volcanic vents between tectonic plates that are spreading apart d)the Hawaiian Islands answer:d
Which major atmospheric component is chiefly a product of life processes?
a)water b)hydrogen sulfide c)oxygen d)carbon dioxide e)nitrogen answer:c
the inner planets formed:
a)when a larger planet broke into pieces. b) when the Sun's heat destroyed all the smaller bodies in the inner solar system. c) in the outer solar system and then were deflected inward by interactions with Jupiter and Saturn. d) by collisions and mergers of planetesimals. answer: d
The _______ states that the Moon formed far from Earth and later became gravitationally bound by Earth after a close encounter.
capture theory
what are the three most important greenhouse gases?
carbon dioxide, methane, and nitrous oxide
According to the _________ Earth and the Moon formed at about the same time out of the same pre-planetary matter.
coformation (or sister) theory
what does the most accurate measurement of the age of the Earth come from?
decay of radioactive elements
Why does Earth have seasons?
due to Earth's inclination angle in relation to the plane of Earth's orbit around the sun
Comparing the rotation and orbital period of the Moon with those of Earth, rank the periods from longest to shortest.
earth's orbital period, (Moons orbital period, Moon's rotation period), earth's rotation period
what are radioactive elements?
elements that are spontaneously changing into other elements(the "decay") and releasing energy
what are the characteristics of a jovian planet?
extensive ring systems numerous orbiting moons primarily composed of hydrogen, helium, and hydrogen compounds low average density
What is differentiation?
heavy, dense material sinks towards the center of the Earth, less dense material floats towards the surface, creating layers
A glancing collision between a large, Mars-sized object and a youthful, molten Earth led to formation of the Moon according to the _________
impact theory
How does the greenhouse effect work?
incoming solar radiation is absorbed in atmosphere by greenhouse gases, infrared radiation from surface is radiated out to space, some goes back into atmosphere
How is radiometric dating used to determine the age of earth?
method used to date rocks and other objects based on the known decay rate of radioactive isotopes
what rocks give the best estimate of the age of the solar system?
moon rocks and meteorites
rank the gravitational tidal force exerted on it by Earth for three different lunar locations. Rank from greatest to least gravitational attraction
near side, midway, far side
what is the planetesimal accretion theory?
planetesimals collide and form larger protoplanets A collision/merger of two protoplanets is the currently accepted theory to explain how the system Earth-Moon was formed
how are tides connected to gravity?
result from gravitational attraction of the sun and moon on the oceans of Earth
What are tectonic plates?
sections into which the earth's basaltic crust is broken
what does the Earth's magnetic field do?
serves to deflect most of the solar wind, that would otherwise strip away the ozone layer
what are the characteristics of a terrestrial planet?
solid, rocky surface small size located within the inner solar system
Mercury and the Earth have about the same average density, but Mercury's core is much larger, compared to the size of the body.
true false answer:true
What is continental drift?
the plates move around on the surface of the Earth, carrying the continents with them
What is the greenhouse effect?
the trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.
Compared to Earth, Venus spins very rapidly.
true false answer:false
An atmosphere can escape a planet if the escape velocity is six times the average molecular speed at that temperature.
true false answer:true
Collisions between low density continental plates create the tallest mountain chains, such as the Himalayas.
true false answer:true
Most of the time, Venus is the third-brightest object in the sky.
true false answer:true
Relative to the size of the planet, Mercury has the largest core of any planet.
true false answer:true
The actual slow rotation of Venus was first found by radar observations from Earth.
true false answer:true
The cause of Venus's slow rotation is unknown at present.
true false answer:true
The continuing rise in the carbon dioxide in our atmosphere should cause our surface temperatures to rise.
true false answer:true
The orbit of Mercury is more elliptical than that of any other terrestrial planet.
true false answer:true
The surface temperature of Venus is 750K, even hotter than Mercury.
true false answer:true
Venus can appear as a crescent through the telescope.
true false answer:true
Venus's rotation period is longer than its year.
true false answer:true
