Astronomy Test 2
What is the difference between a differentiated body and an undifferentiated body, and how might that influence a body's ability to retain heat for the age of the solar system?
- A differentiated body is one that has been heated to the point where it is liquid, and heavier, denser materials sink to the center of the planet, and the lighter elements rise to the outer layer. -Undifferentiated bodies were never heated enough for the elements to separate; they cool quickly and are typically smaller in size. - The concentration of materials helps to retain heat in the interior of a planet.
How was Pluto discovered? Why did it take so long to find it?
Pluto was discovered from comparisons of photographs taken several days apart that showed the relative motion of Pluto against a background of stars. Pluto was difficult to find because of its small size and great distance from Earth
What are the seasons like on Jupiter?
There is no difference between the seasons because of the small axis tilt
Moon with the thickest atmosphere
Titan
Compare the properties of Titan's atmosphere with those of Earth's atmosphere.
Titan's atmosphere is four times denser than Earth's atmosphere at the surface, even though both atmospheres are mostly nitrogen. However, 20% of Earth's atmosphere is oxygen; Titan's atmosphere is 98% nitrogen, with no free oxygen in it.
A continued rise in the level of greenhouse gasses in Earth's atmosphere will cause our planet's temperature to increase.
True
Although Saturn's ring system is tens of thousands of kilometers wide, it is only a few tens of meters thick.
True
During the northern summer of Uranus, an observer near the north pole would observe the Sun high and almost stationary in the sky.
True
In general, a storm system in Jupiter's atmosphere is much longer-lived than storms in Earth's atmosphere.
True
Io has a noticeable lack of impact craters on its surface.
True
Lava flows are common on the surface of Venus.
True
Mars at times is engulfed by global dust storms.
True
Mercury's solar day is actually longer than its solar year
True
Most of the moons of Uranus have orbits that share the tilt of the planet.
True
Most planets orbit the Sun in nearly the same plane as Earth.
True
Neither Mercury nor the Moon has any significant atmosphere
True
The composition of the ring particles of Saturn is predominantly water ice.
True
The main constituents of Jupiter are hydrogen and helium.
True
The orange-red color of the Martian surface is primarily due to rust (iron oxide) in its soil.
True
The surface of Europa is completely covered by water ice.
True
The total mass of all the planets is about half the mass of the Sun.
True
Unlike the Moon, Mercury is differentiated.
True
Uranus and Neptune have very similar rotation rates.
True
the planet with a diameter closest to Earth's
Venus
We believe that Venus, Earth, and Mars all started with a significant supply of water. Explain where that water is now for each planet.
Venus and Mars water left atmosphere (evaporated in sun) or froze (on parts with no sunlight)
Jupiter is denser than water, yet composed for the most part of two light gases, hydrogen and helium. What makes Jupiter as dense as it is?
intense atmospheric pressure gradually turns the light gasses into dense fluids
Densest moon
io - Jupiter
What is, by far, the most abundant component of Earth's atmosphere?
molecular nitrogen, N2 (78%,)
What evidence is there that Venus was volcanically active about 300-600 million years ago?
there are craters on Venus that are 300-600 million years old, and the surface has not changed so it was only active in that time
The largest satellite (moon) in the solar system is: A. Ganymede B. Titan C. Earth's Moon D. Charon E. Io
A. Ganymede
The planet that orbits "on its side" (i.e. has its rotation axis perpendicular to the plane of its orbit) is: A. Uranus B. Neptune C. Pluto D. Jupiter E. Saturn
A. Uranus
Astronomers believe that Mars formed with a much thicker atmosphere than it has today. Where did this atmosphere go? A. it escaped into space (and some later froze out as Mars got cold) B. it was absorbed by the rocks on Mars, which are much more absorbent than on Earth C. it was drawn into the crust and mantle of Mars through the enormous cracks of the Mariner Valley canyon system D. it is trapped in bubbles inside the rocks on the Martian surface E. no one has any good theories about this; it is an unsolved mystery
A. it escaped into space (and some later froze out as Mars got cold)
The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturn's magnetism is: A. gold B. helium C. hydrogen D. water E. vanallenium
C. hydrogen
What features are abundant on Callisto and Ganymede and almost absent on Europa and Io? A. volcanoes B. markings that show the surface is made of ice C. impact craters D. lakes and pools of liquid ammonia E. rings
C. impact craters
Which of the following characteristics distinguishes Uranus from every other planet in our solar system? A. it has more than one moon B. its atmosphere is made of gases C. it rotates on an axis tilted almost 90 degrees to the circle of its orbit D. its orbit is significantly tilted relative to the orbits of the other planets E. its magnetic axis does not lie in the same direction as its rotation axis
C. it rotates on an axis tilted almost 90 degrees to the circle of its orbit
The inner planets are made mostly of rock and metal because: A. lighter materials cannot orbit the Sun; they would fall in immediately B. the Sun is made mostly of rock and metal and the inner planets are closest to the Sun C. it was so hot where the inner planets formed that the lighter materials evaporated D. Jupiter's large gravity immediately attracted all the lighter materials, and so there were few light atoms left by the time the inner planets were ready to form E. this is an unsolved problem in astronomy
C. it was so hot where the inner planets formed that the lighter materials evaporated
The mountains on Pluto are made of frozen water, which at Pluto temperatures, is as hard as rock. Pluto also has a smooth, round basin which could be thought of as a frozen sea. What material is in the basin (nicknamed Sputnik) likely to be made of? A. warmer water B. carbon dioxide (dry ice) C. nitrogen D. complex carbon compounds which are the building blocks of life on Earth E. helium
C. nitrogen
the most massive moon
Ganymede
the largest moon in the solar system
Ganymede (Jupiter)
Outline the main events in the Moon's geological history.
- After its formation, the low density silicates cooled first and made up the initial crust. This surface was exposed to heavy meteor cratering early in the Moon's history. - About 3.8 to 3.3 billion years ago, extensive volcanism released large amounts of lava that flowed over the surface filling in the lowest parts of the large impact basins and forming the darker maria we see today. - Both the highlands and the maria continue to be battered by additional impacts ever since.
What are Earth's core and mantle made of? Explain how we know.
- The mantle is made of rock, which we know from chemical analysis of samples from the upper mantle material that is ejected occasionally from volcanoes. -The elements residing in the core are primarily, but not limited to, iron and nickel. - Density calculations show that Earth's core is metal.
What do our current ideas about the origins of the Moon and Mercury have in common? How do they differ?
- both suffered frequent and sometimes massive impacts early in their histories, with heavily cratered surfaces visible on each body. - Mercury has much more iron than the Moon, so early on, Mercury must have lost most of its rocky mantle, probably due to impacts. - Mercury shrank enough to create long "wrinkles" and scarps in the crust; such scarps are not seen on the Moon.
Describe the current atmosphere on Mars. What evidence suggests that it must have been different in the past?
- mostly of carbon dioxide, but is very thin, less than 1% of Earth's atmosphere. -water on Mars in the past means that the atmosphere was thicker and warmer, or water would have evaporated away very quickly.
How are Triton and Pluto similar?
-Both very cold worlds in the outer reaches of the solar system -similar in size -similar density -similar proportion of rock and ice that makes them up. -Both have a thin atmosphere of nitrogen, which freezes and sublimates depending on the temperature -irregular or unusual orbits
Compare the geology of Callisto, Ganymede, and Titan
-Callisto is an ice-covered moon whose inner materials have never fully differentiated into different-density layers. It has no inner or outer activity and is basically geologically dead. -Ganymede has a central rocky core and shows signs of tectonic activity, including regions of young surface terrain and long cracks in the crust. -Titan has similar mass, size, and composition to Callisto and Ganymede, but has an active geology of liquid hydrocarbons on the surface, evaporation into the atmosphere, and rain back onto the surface.
What are the main atmospheric heat sources of each of the giant planets?
-For Jupiter, Saturn, and Neptune, both sunlight and internal sources provide energy to the atmosphere. -Uranus has no or very little internal heat, so it gets its energy from the Sun -"The extra heat source on Neptune [and Jupiter and Saturn] is largely due to gravitational contraction
What evidence do we have that there was running (liquid) water on Mars in the past? What evidence is there for water coming out of the ground even today?
-Images from orbiting spacecraft of runoff channels and outflow channels all show evidence of formation by running water. -Several dry basins contain minerals that only form with water -dark streaks that got longer over the course of several days showed spectra of hydrated salts, and may be evidence of saltwater on Mars today
What are the visible clouds on the four giant planets composed of, and why are they different from each other?
-Jupiter and Saturn clouds are primarily crystals of frozen ammonia -On Uranus and Neptune, the clouds are composed of methane. -The temperatures dictate the cloud composition. For Jupiter and Saturn, the temperatures keep methane in a gaseous state, while on Uranus and Neptune, the colder temperatures allow the methane to freeze and condense into clouds.
Describe the different processes that lead to substantial internal heat sources for Jupiter and Saturn. Since these two objects generate much of their energy internally, should they be called stars instead of planets? Justify your answer.
-Jupiter generates heat by slow contraction, which liberates substantial gravitational energy. -A significant part of Saturn's heat comes from the release of gravitational energy from helium separating from the lighter hydrogen and sinking to its core. -They are not large enough (by a significant factor) to support nuclear reactions in their interiors, and so are not considered to be stars.
Describe and compare the rings of Saturn and Uranus, including their possible origins.
-Saturn's rings form a wide and complex system, consisting mostly of particles and pieces of ice, and are highly visible. -They may have formed from one or more moons that broke up due to a collision, or are left over from early debris that never coalesced into a moon. -The rings of Uranus are thin and hard to see, consisting mostly of chunks of carbon and hydrocarbons with very little reflectivity. -They may also have formed from the breakup of a small moon due to a collision. They may be kept thin by the presence of shepherd moons.
How might Venus' atmosphere have evolved to its present state through a runaway greenhouse effect?
-Sun evaporated water on Venus, releasing carbon dioxide. -The carbon dioxide prevented infrared radiation from escaping the planet, leading to a rise in temperatures and of water and release of carbon dioxide. -Sunlight would break up water vapor molecules higher in the atmosphere into hydrogen, which escaped the planet, and oxygen, which combined with surface rocks. -The loss of water reduces the planet's ability to absorb carbon dioxide.
Describe three ways in which the presence of life has affected the composition of Earth's atmosphere
-The development of plants such as blue-green algae, which processed CO2 and released oxygen as a waste product, increased the amount of oxygen in the atmosphere and decreased the amount of CO2. -Eventually, as the plant life population increased, the ozone layer was created. -Currently, human industrialization is releasing an increasing amount of CO2 into the atmosphere, causing climate change.
Valles Marineris is similar in size to Earth's Grand Canyon.
False
What does a planet need in order to retain an atmosphere? How does an atmosphere affect the surface of a planet and the ability of life to exist?
-The gravity of a planet helps to determine whether an atmosphere can be retained. Mars has a shallow atmosphere compared to Earth, but it is also only 1/3 the size of Earth. Venus and Earth are about the same size and both have atmospheres. - A dense atmosphere insulates the surface of a planet so that more heat is retained; however, the composition of the atmosphere is also important. Certain gasses lead to a greenhouse effect, allowing the planet to be warmer than you would expect from its position around the Sun. Life as we know it requires temperatures and pressures at which water is liquid.
What is the evidence for a liquid water ocean on Europa, and why is this interesting to scientists searching for extraterrestrial life?
-The surface of Europa features jagged blocks of ice that seem to have rotated and collided with one another, which would not likely happen on a solid moon. -a weak magnetic field implies the presence of a liquid layer below the surface.
Summarize the four main hypotheses for the origin of the Moon.
1) The fission hypothesis suggests that the Moon was once part of Earth but separated early in their history. 2) The sister hypothesis proposes that the Moon formed together with, but independent of, Earth. 3)In the capture hypothesis, the Moon formed elsewhere in the solar system and was later captured by Earth. 4)The newer giant impact hypothesis suggests that a Mars-sized object grazed Earth, ejecting material from both Earth and itself—material that condensed to form the Moon.
The largest volcano on Mars is called: A. the Red Spot B. Olympus Mons (Mt. Olympus) C. Mariner Valley D. Hellas E. Mount Maxwell
B. Olympus Mons (Mt. Olympus)
The satellite which has the thickest atmosphere (so thick that it's quite a surprise for a satellite) is: A. Triton B. Titan C. the Earth's Moon D. Europa E. Callisto
B. Titan
Of the following planets, which do NOT have satellites (moons)? A. Mars B. Venus C. Earth D. Jupiter E. you can't fool me, all the planets have satellites
B. Venus
By far the most abundant element in the giant (jovian) planets is: A. helium B. hydrogen C. oxygen D. nitrogen E. silicon
B. hydrogen
If you were to take a large sample of the four giant planets, the most common element you would find in them is: A. iron B. hydrogen C. oxygen D. silicon E. you can't fool me, there are equal amount of ALL the elements in those planets
B. hydrogen
About 75% of the surface of Venus consists of A. high volcanic plateaus, many of which are currently erupting lava B. lowland lava plains C. wall-to-wall impact craters D. vast criss-crossing channels carrying liquid lava E. lush jungles growing very effectively because it is so warm and humid there
B. lowland lava plains
The most likely models of the planet Mercury indicate that more than half the planet may be composed of: A. water B. metals C. ammonia and methane ice D. very light and porous rocks E. the element mercury
B. metals
Which element plays the same role on Titan as water does on Earth (existing as gas, liquid, and solid)? A. carbon dioxide B. methane C. ammonia D. hydrogen cyanide E. propane
B. methane
Which element plays the same role on Titan as water does on Earth (existing as gas, liquid, and solid)? A. carbon dioxide B. methane C. ammonia D. hydrogen cyanide E. propane
B. methane
What is one way that we humans are currently making the atmosphere of the Earth more like that of Venus? A. we are adding more oxygen to the atmosphere by growing more plants and trees B. we are adding carbon dioxide and other greenhouse gases to the atmosphere, which is leading to global warming C. we are setting up a lot of equipment at the north and south poles to cool our planet down D. we have more than doubled the mass of the Earth's atmosphere by making additional air in our factories E. the Earth's atmosphere already resembles the atmosphere of Venus in all ways that are significant
B. we are adding carbon dioxide and other greenhouse gases to the atmosphere, which is leading to global warming
What evidence can you give that shows the surface of Jupiter's moon Europa must be relatively young? A. there are thousands of active volcanoes on Europa's surface B. we see very few craters compared to the surfaces of Callisto and Ganymede C. radioactive rocks from Europa that have been brought back to Earth by our probes show that Europa is a young moon D. the interior of Europa is made of metals like iron and nickel E. Europa was not orbiting Jupiter when Galileo observed its moons, but now it is
B. we see very few craters compared to the surfaces of Callisto and Ganymede
With no wind or water erosion of rocks, what is the mechanism for the creation of the lunar "soil?"
Billions of years of impacts breaking up the rocks and scattering the debris over the surface have created lunar "soil." Enough impacts have occurred to cover much of the surface with sand- and dust-sized particles.
What makes astronomers believe that Mars once had rivers and running water? A. there is a grand canyon system about 2,500 mi long on its surface (all of it made by running water) B. the volcanoes today show evidence of water coming from their highest points and running down (implying this would have happened even more long ago) C. Images from orbiting spacecraft reveal ancient channels that look like dried-up river beds on Earth (and our rovers show geological formations made by running water) D. giant basins (like Hellas) show evidence of being filled with frozen water that was once probably a sea E. you can't fool me, there is no evidence at all that Mars ever had any water
C. Images from orbiting spacecraft reveal ancient channels that look like dried-up river beds on Earth (and our rovers show geological formations made by running water)
The primary clouds in the atmospheres of Jupiter and Saturn are composed of: A. water vapor B. iron and nickel C. frozen ammonia crystals D. metallic hydrogen E. frozen alcohol (ready to make cocktails)
C. frozen ammonia crystals
During the process of differentiation, A. satellites separate from the parent planets and go into their own orbits B. the faster planets move further out from the Sun C. heavier materials sink to the centers of molten planets D. the atmosphere of a planet changes from oxidized to reduced E. the surface of a planet changes to resemble Bayonne, New Jersey
C. heavier materials sink to the centers of molten planets
Venus has a retrograde orbit around the Sun
False
The lunar highlands are made mostly of rocks that A. fell on to the Moon from space B. were recently expelled by volcanoes from the deep interior of the Moon C. rose to the top as the Moon cooled from a molten state early in its history D. that were pushed upwards due to active plate tectonics on the Moon E. don't have a good scientific explanation yet
C. rose to the top as the Moon cooled from a molten state early in its history
Our modern understanding of Pluto is that it is a member of A. the asteroid belt B. the giant planets C. the Kuiper Belt (of trans-Neptunian objects) D. the terrestrial planets E. no grouping within our solar system; it is completely one-of-a-kind
C. the Kuiper Belt (of trans-Neptunian objects)
What is the cause of its many volcanic/geyser-like eruptions on the moon Io? A. its surface is at the triple point of methane, where it can be gas/liquid/solid B. Jupiter's magnetic field causes huge bolts of lightning to hit Io and heat the surface C. the gravitational stress of being so close to Jupiter and its other large moons heats the Io's inside D. there is a metallic magnetic layer inside Io which is explosive E. inhabitants of Io are intercepting Earth TV transmissions; it's making them throw up
C. the gravitational stress of being so close to Jupiter and its other large moons heats the Io's inside
What formation or formations are evidence that the planet Mercury may have shrunk (gotten a bit smaller) as it cooled? A. the Caloris basin B. the large basins in general C. the long scarps or cliffs D. the thin atmosphere emerging from inside the planet E. the big ticket with size 8 crossed out and size 6 written in
C. the long scarps or cliffs
Which of the following statements about the geysers on the moon Triton is true? A. they are caused by the impact of small comets on Triton's fragile surface B. the geysers are sulfur volcanoes which stick out of Triton's crust C. they involve plumes of nitrogen on the sunlit side of Triton D. they are caused by collisions with the rings of Neptune E. they are only visible when it is winter on Triton
C. they involve plumes of nitrogen on the sunlit side of Triton
Which of the following statements about the seasons on Jupiter is correct? A. Jupiter has seasons pretty much like the Earth; its axis has the same tilt, and each season is about the same length B. Jupiter has the same axis tilt as the Earth, but each season on Jupiter is much longer C. Jupiter's axis is tilted much more than the Earth's so its seasons are much more intense D. Jupiter's axis is hardly tilted so it has no real seasonal variations E. Jupiter's orbit brings it much closer to the Sun in summer and much farther from the Sun in winter
D. Jupiter's axis is hardly tilted so it has no real seasonal variations
Which of the following statements about the rocks brought back from the Earth's Moon by the astronauts is TRUE? A. The Moon rocks resemble Earth rocks in every detail B. The Moon rocks are fundamentally different from Earth rocks, with materials never seen on Earth C. The Moon rocks did not survive long enough in the Earth's oxygen-rich atmosphere for us to analyze them D. The Moon rocks were puzzling, because they resemble rocks from the Earth's crust in many ways, but also have subtle differences E. The Moon rocks resemble many of the main dishes in our college cafeteria
D. The Moon rocks were puzzling, because they resemble rocks from the Earth's crust in many ways, but also have subtle differences
The smaller objects in the solar system made of rock and metal (most of which orbit between Jupiter and Mars) are called: A. comets B. satellites C. Titius-Bode objects D. asteroids E. silicates
D. asteroids
In studying the surfaces of solid bodies in the solar system, astronomers have learned that the number of craters (per unit area): A. is about the same on every world B. is greater as you get closer to the Sun C. is greater as you get further and further from the Sun D. is roughly proportional to the age of the surface we are examining E. follows no discernible rules or relationships at all
D. is roughly proportional to the age of the surface we are examining
The bluish color that makes the atmosphere of Neptune so beautiful to the human eye is caused by the interaction of sunlight with what gas? A. carbon dioxide B. oxygen C. argon D. methane E. helium
D. methane
Water vapor is abundant in the atmosphere of Venus.
False
Earth's average density is less than the density of water
False Earth's density is 5500 kg/m3 Waters density is 1100 kg/m3
What makes astronomers think that impact rates for the Moon must have been higher earlier than 3.8 billion years ago? A. all the radioactive rocks found on the Moon so far give ages much younger than that, so the Moon must have formed less than 3.8 billion years ago B. we see many more craters on the Moon that have been eroded by wind and rain C. all the large craters on the Moon come in pairs, while all recent craters are single D. there are ten times more craters on the older highlands than the younger Maria E. the ancient sea basins on the Moon, whose water has since evaporated, show a lot more cratering
D. there are ten times more craters on the older highlands than the younger Maria
What makes the rings of Neptune different from those of other planets we know? A. they are much thinner B. they have gaps and divisions in them C. they are much darker D. they are clumpy (or bulging) in places E. there is more than one ring in the system
D. they are clumpy (or bulging) in places
Two worlds in the outer solar system that seem remarkably similar to each other are: A. Titan and Ganymede B. Io and Europa C. Titan and Triton D. Callisto and Io E. Pluto and Triton
E. Pluto and Triton
The Red Spot of Jupiter is: A. variable in size B. a high pressure storm system in the atmosphere C. made of a reddish colored material (but we don't know what gives it the reddish color) D. long-lived (observed since the 1600's) E. all of the above
E. all of the above
Astronomers estimate that the plains of Venus are only about 500 to 600 million years old. How do they estimate dates like this? A. by looking for little brass plates that give the founding date and the name of the governor at the time B. by looking at the radioactive rock samples that have been returned to Earth from Venus C. by noting that all the plains on all the terrestrial planets have the same age D. by seeing how much the continental plates on which the Venus plains are floating have spread apart E. by counting the craters visible on the surface and comparing crater counts to other worlds
E. by counting the craters visible on the surface and comparing crater counts to other worlds
The same gas makes up most of the atmosphere of Mars and Venus. This gas is: A. water vapor B. nitrogen C. ozone D. ammonia gas E. carbon dioxide
E. carbon dioxide
Which of the following is NOT a way that Jupiter differs from terrestrial planets? A. its average density is lower B. it is farther away from the Sun C. it includes much more gas and liquid D. it is larger in diameter E. its surface has many more craters from early collisions
E. its surface has many more craters from early collisions
Which of the following ways that jovian (giant) planets differ from the terrestrial planets is NOT CORRECT? A. jovians have more mass than the terrestrials B. jovians are further from the Sun than terrestrials C. jovians are made of lighter elements on average than terrestrials D. jovians have rings while terrestrials do not E. jovians (being larger) rotate significantly more slowly than terrestrials
E. jovians (being larger) rotate significantly more slowly than terrestrials
The upper clouds in the atmosphere of Neptune are composed of: A. frozen water crystals B. liquid hydrogen C. iron crystals caught in the magnetic field lines D. carbon dioxide E. methane
E. methane
excluding the Jovian planets, the planet where you would weigh the most on its surface (Hint: Weight is directly proportional to surface gravity.)
Earth
the densest planet
Earth
Contrast the mountains on Mars and Venus with those on Earth and the Moon.
Earth and Venus have extensive mountains of both a volcanic and tectonic origin but Venus has taller ones because it has less erosion. On Mars, all the large mountains are volcanoes, and on the Moon, the rings of mountains were produced by impacts. Mars is the tallest because the smaller the planet the larger the mountains.
All planets have moons.
False
Earth's atmosphere is composed primarily of oxygen.
False
Jupiter's ring is made up of icy particles a few meters across.
False
Large craters are formed frequently today on the surface of the Moon.
False
Pluto is larger than Earth's Moon
False
Samples of Earth's core are available from volcanoes
False
Saturn probably does not have a rocky core
False
The Moon rotates on its axis about once per week.
False
The largest planets also have the largest densities.
False
The other terrestrial planets all rotate more rapidly than Earth.
False
The ozone layer is the warmest part of Earth's atmosphere.
False
The rotation of Saturn is unlike that of Jupiter; it is slow and shows little differential rotation
False
There is one high tide and one low tide per day at any given coastal location on Earth
False
Uranus and Neptune are comparable in size and are larger than the other two jovian planets.
False
the planet that takes the shortest time to rotate
Jupiter
the smallest planet. the planet that takes the longest time to rotate
Mercury
What is the main consequence of Mercury's orbit being so highly eccentric?
Mercury's distance from the Sun varies hugely, ranging from 46 million km at perihelion to 70 million km at aphelion
List the possible interactions between Earth's crustal plates that can occur at their boundaries.
Rift zones, where plates pull apart; subduction zones, where one plate slides over another; faults, where plates slide alongside each other; , plates can collide and crumple, creating mountains.
the least-dense planet
Saturn
What is the composition of the polar caps on Mars?
Seasonal ice caps are made up of dry ice, or crystals of frozen carbon dioxide; the northern residual cap is water ice, whereas the southern permanent ice cap is made predominantly of water ice with a covering of carbon dioxide ice.
How do terrestrial and giant planets differ? List as many ways as you can think of
Terrestrial Planets: lie closer to the Sun, are small compared to the giant planets, have relatively high densities, and are made of mostly silicates and metals
Why are there so many craters on the Moon and so few on Earth?
The Moon lacks water, an atmosphere, and tectonic activity, three forces that erode Earth's surface and erase all but the most recent impacts.
Suppose you miraculously removed all of Saturn's moons. What would happen to its rings?
The Rings would gradually expand
What are the main challenges involved in sending probes to the giant planets?
The main challenge involved in sending probes to the Giant planets is that the Giant planets are solely made up of gas, hence there is no surface to land the probes on. Also, because of the crazy atmosphere on these planets, the probes would most likely get destroyed once they hit the atmosphere of the planets.
What is the source of Earth's magnetic field?
The main source of earth's magnetic field is the metals present in earth core and the few present in the crust.
Why do the upper levels of Neptune's atmosphere appear blue?
The methane is part of what gives Neptune its brilliant blue tint, as it absorbs red light and reflects bluer colors
At the pressures in Jupiter's interior, describe the physical state of the hydrogen found there.
The pressure is so high that the hydrogen, normally a gas, has been compressed into a liquid-metallic form not seen on Earth
The largest part of the Earth is its a. oceanic crust b. continental crust c. mantle d. core e. atmosphere
c. mantle
Scientists now understand that the Earth consists of layers, with the densest materials in the core. What allowed the differentiation of the Earth's layers to happen? a. a giant rock from space hit the Earth and made a huge hole almost to the center, through which material could move b. continental drift and plate tectonics made this happen c. the early Earth must have been so hot it was like a liquid and heavier things sank to the middle d. this is one of the things that happened in the last few thousand years because of global warming e. this is an unsolved problem; scientists have no good ideas about this at all
c. the early Earth must have been so hot it was like a liquid and heavier things sank to the middle
One way in which the ozone layer is useful for life forms on the Earth's surface is that it a. presses down on the continental plates, and makes it more difficult for them to slip b. keeps the heat of the Sun from escaping, making the Earth a bit warmer c. is so thick that meteors from space all burn up there, regardless of size d. absorbs ultra-violet light, preventing much of it from reaching the surface e. glows brilliantly at sunset, making scenes that lovers can enjoy
d. absorbs ultra-violet light, preventing much of it from reaching the surface
Which of the following is a way we believe that the early atmosphere of the Earth differed from the atmosphere we have today? a. there was little if any free oxygen early on b. there was no ozone layer early on c. there was probably more carbon dioxide early on than there is today d. all of the above e. none of the above
e. none of the above
According to the theory of plate tectonics, a. the continents are moving but the ocean floor is not, leading to great friction b. the rubbing of the waters of the Earth across its crust is speeding up its rotation c. the liquid metal inside the Earth is developing plates of solid metallic material, which contribute to the Earth's magnetic field d. earthquakes are caused by huge waves that come up from inside the molten core of the Earth e. slow motions within the mantle of the Earth move large sections of the crust around
e. slow motions within the mantle of the Earth move large sections of the crust around
Describe the basic internal structure of Mercury
one of the densest of the planets, at 5.4 g/cm3. It has an enormous iron-nickel core nearly 3500 km in diameter, which is encased in a rocky/silicate crust about 700 km deep. The metallic core, representing nearly 60% of the planet's total mass, produces a weak magnetic field.