FINAL Flashcards
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.
D. a cool nebula of gas and dust.
Astronomers estimate that the solar nebula from which the solar system formed began as a cloud that was approximately _____ in diameter.
1000 au
The Kuiper belt is
Located beyond the orbit of Neptune
When a rotating cloud of gas and dust contracts gravitationally, conservation of angular momentum causes its speed of rotation to
increase
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?
conservation of angular momentum
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.
snow
One aspect of the solar system that astronomers believe makes it unique from other exoplanet systems discovered so far is that _____.
our early gas giants stabilized their orbits and didn’t spiral in toward the Sun
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.
nuclear fusion
Which of these describes what happens to a comet in a highly elliptical orbit as it passes near the Sun.
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.
Under the pull of gravity, if an object has a large enough mass, astronomers expect that it will be _____ in shape.
round
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 moon of Saturn
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?
dwarf planet
The characteristic that is NOT true of the terrestrial planets is:
a relatively low density compared to the Jovian planets.
The characteristic that is NOT shared by all giant planets is
heavily cratered surfaces.
The majority of the 175 known planetary moons in the solar system are NOT _____ in shape.
spherical
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?
This exoplanet is likely a terrestrial planet
What aspects of a planet tend to contribute to a large albedo?
cloud cover
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?
This planet could likely have a significant number of satellites in orbit around it.
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?
carbon dioxide and water vapour
The greenhouse effect occurs because:
some gases absorb infrared radiation.
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.
oxygen
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?
oxygen
Which of these would NOT be a result if Earth’s interior had cooled significantly since its formation?
Earth’s atmosphere would be much thicker than currently.
The majority of the mountains seen on the Moon were created by:
major impacts early in the Moon’s history.
A _____ is a lava floodplain covering the floor of an ancient asteroid impact basin.
mare
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.
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.
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.
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.
Astronomers have calculated that the rate at which the Moon is moving away from Earth is approximately 3.8 _____ per year.
centimetres
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
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
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
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
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
The process by which gasses trapped in rocks below the surface are released into Mercury’s thin atmosphere is known as _____.
Outgassing
A small planet or satellite would be expected to have all of these characteristics EXCEPT:
a large iron core
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.
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.
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.
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.
The surface of Venus consists primarily of:
rolling plains and low hills with two major, continent-size highland regions.
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.
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.
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.
The yellowish color of Venus’s permanent cloud cover is due to the presence of _____ in the atmosphere.
sulfur
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
How long ago do astronomers believe that Mars tectonic plate activity stopped?
4 billions years ago
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
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.
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
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.
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
What is the Kelvin—Helmholtz mechanism?
the release of gravitational potential energy as heat when a body contracts and cools
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.
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
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.
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
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
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.
The atmosphere of Titan, the largest satellite of Saturn, is mostly nitrogen with a significant amount of _____.
methane
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.
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.
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.
Neptune was discovered in 1846 by _____.
Johann Galle
Urbain Leverrier
John Couch Adams
William Herschel
Johann Galle
Which planet has the fastest measured wind speeds in the solar system?
Jupiter
Saturn
Uranus
Neptune
Neptune
Due to the extremely cold 73 K temperature at the top of Uranus’s atmosphere, the clouds there are composed of _____ ice crystals.
methane
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.
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
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.
The largest asteroid in the inner solar system is named _____, which is also classified as a dwarf planet.
Ceres
No comets exist in the asteroid belt between Mars and Jupiter because the asteroid belt is inside the Sun’s _____.
snow line