Astronomy Quiz 4
5. Oort cloud asteroids have a composition that is very different than planets because A. they formed in a region of the solar system that had a different composition of solid particles. B. they formed at a different time than the rest of the planets. C. their low gravity prevents them from holding volatile gasses. D. All of the above. E. C and A
E. C and A
How do we refer to the apparent contradiction between high estimates of the probability of the existence of intelligent extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations ?
Fermi paradox
We said in class that Saturn would float in a bathtub because
Saturn is less dense than water
Planets and most asteroids rotate with similar periods (5-10 hours). What would be responsible for slowing this rotation?
Tital Forces
At the surface, Titan is most similar to
Triton
Europa is a close-in moon of Jupiter with active volcanoes that flow with essentially water lava. This activity means that the surface of Europa is
geologically young
Other than dust-sized particles, what is the most common size of particles making up Saturn's bright rings? (a) about a centimeter in diameter (b) 10-30 centimeters in diameter (c) 1-10 meters in diameter (d) 10-100 meters in diameter
A. about a centimeter in diameter
Our theory of the origin and evolution of the solar system cannot account for which fact about the solar system?
Bode's Law
15. Measurements of the mean densities of the gas giants from fly-by missions argue that their deepest centers are most similar to A. dry ice B. water ice C. terrestrial planets D. metallic hydrogen E. DNA
C. terrestrial planets
What feature do all three outer Galilean satellites of Jupiter (Europa, Ganymede, and Callisto) appear to share? (a) highly modified surfaces showing very few ancient craters (b) active geysers and plumes of volcanic gases (c) ancient, densely cratered surfaces (d) an ocean of liquid water beneath an icy crust
D. an ocean of liquid water beneath an icy crust
Who first calculated the orbits of comets based on historical records dating back to antiquity?
Edmund Halley presented the calculations for 24 cometary orbits in 1705. One of these he predicted to return to the vicinity of Earth in 1758. That comet, which did indeed return as predicted, is now known as Halley's Comet.
Why is Saturn's moon Epimetheus notably less round than some other moons?
Epimetheus is not very massive
While the inner, terrestrial planets are mostly dense and metal-rich, we find that the outer, giant planets are mostly composed of
Hydrogen
Which planets have large obliquity (tilt between equatorial and orbital planes) instead of small obliquity like most planets?
Mercury and Pluto
Why is a body like Neptune very nearly spherical while an asteroid is not?
Neptune has enough self-gravity to make it spherical due to its mass.
Why are some planets and moons more geologically active than others?
Smaller bodies radiate internal heat faster than bigger bodies. Smaller bodies become geologically dead faster.
What plane does the rotational equator of the sun lie in?
The same orbital plane of the planets
Which of the following is NOT true of the asteroid belt
it likely represents bits of a planet that was destroyed
Pluto is generally regarded as an enigma, or puzzle. This is because
it has a small mass, and a highly eccentric orbit
The ring system of Saturn most probably resulted from
the movement of a large moon within Saturn's Roche limit, where tidal forces ripped the moon apart
The whitish clouds that are visible in photographs of Neptune consist of (a) water ice crystals. (b) ammonia crystals with phosphorus impurities. (c) dry ice (carbon dioxide) crystals. (d) methane ice crystals.
(d) methane ice crystals.
According to our in class estimate, what is the prediction from the Drake equation for the number of intelligent civilizations in our galaxy?
1
Saturn's moon Enceladus shows several "tiger stripes." These stripes are believed to result from (a) a major impact early in Enceladus's history. (b) tidal interaction with another major moon of Saturn. (c) a liquid ocean below the icy crust. (d) convection in Enceladus's icy mantle, similar to convection in the Earth's mantle.
C. a liquid ocean below the icy crust.
4. Pluto has a thin atmosphere. What is its color? A. blue B. dusty brown C. green D. it's too thin to tell E. yellow
C. blue
Describe the nucleus of a typical comet and compare it with an asteroid of similar size.
Cometary nuclei are quite small, on the order of a few kilometers in diameter, and are composed of ices, volatile organic compounds, silicate grains, and dust. Asteroids of similar size are denser and contain more stony and/or metallic materials. Comets react strongly to solar heating, releasing gases and dust, sometimes forming long tails that point away from the Sun.
The most abundant element in the Solar System, as well as the rest of the Universe, is
Hydrogen
Describe the interior heat source of Saturn.
Saturn's excess heat is generated by the precipitation of helium into its metallic hydrogen core. The heavier helium separates from the lighter hydrogen and drops toward the center, somewhat like the heavier ingredients of a salad dressing that hasn't been shaken for awhile. Small helium droplets form where it is cool enough, precipitate or rain down, and then dissolve at hotter deeper levels. As the helium at a higher level drizzles down through the surrounding hydrogen, the helium converts some of its energy to heat. In much the same way, raindrops on Earth become slightly warmer when they fall and strike the ground; their energy of motion - acquired from gravity - is converted to heat.
Which object in the SS has the most mass?
The Sun
T/F Planetary orbits are nearly circular?
True
Which of the following has/have rings? a. Jupiter b. Uranus c. Saturn d. all of the above
d. all of the above
Our most successful model for the formation of the solar system consists of the gravitational collapse of a giant interstellar cloud of gas and dust. If we note that we observe many such clouds within our own galaxy, we may reasonably conclude that
stars are continually being formed in the galaxy
The most convincing verification of our basic theories about the formation and evolution of our solar system comes from observations of
the moons of Jupiter and Uranus
Tidal effects from the sun are responsible for
the relatively slow rotation of the inner planets
What evidence suggests that the outermost moons of Jupiter were captured rather than being formed at the same time as Jupiter?
they have retrograde and eccentric orbits
The intense geological activity (sulfur geysers/volcanoes) observed on Io seems to be connected with
tidal heating from Jupiter
19. The ionized gas tails of comets always point in which direction due to their interaction with the magnetic field lines from the solar wind? A. towards the sun B. curved toward the sun C. away from the sun D. curved away from the sun
C. away from the sun
There is strong evidence that Saturn's largest satellite, Titan, has (a) cryovolcanoes of slushy liquid nitrogen "lava." (b) lakes and rivers of salty water. (c) lakes and rivers of liquid methane and ethane. (d) hydrocarbon geysers erupting from subsurface reservoirs of methane and ethane.
C. lakes and rivers of liquid methane and ethane.
T/F The orbits of the planets lie in roughly the same plane
True
The particles in the rings of Uranus and Neptune are very dark. This is thought to be because they are composed partly of
methane ice, damaged by impact by electrons from the magnetosphere: radiation darkening.
Erosion on the surface of Callisto, Jupiter's outermost Galilean moon, is most likely caused by
sublimation of water ice
Comets change from dirty snowballs in appearance to beautiful objects with tails when
the Sun boils off the gases and pushes away the dust
What do we mean by primitive material? How can we tell if a meteorite is primitive?
the debris of the processes that formed the solar system some 4.5 billion years ago. for the most part, we know it is primitive if it falls from space and by subjecting the rock to laboratory testing
What is Bode's Law?
-Distances between planets usually obeys this law -Rough rule that predicts the spacing of the planets in the SS -Relationship first pointed out by Johann Titus in 1766, formulated into a mathematical expression by JE Bode in 1778 -Works for Uranus, Jupiter, and their moons
6. Why is Io volcanically active, unlike our own Moon? A. Io is heated by the radiation of Jupiter, just like light from the Sun keeps Mercury hot. B. The strong tidal forces of Jupiter heat the planet (via tidal friction). C. Io is composed of materials that melt really easily. D. A runaway greenhouse effect due to Io's thick atmosphere keeps it warm. E. Io is much more massive, so it hasn't cooled since its formation, similar to the Earth itself.
B. The strong tidal forces of Jupiter heat the planet (via tidal friction).
How many magnetic field components does Jupiter's satellite, Ganymede, have? (a) One: a relatively strong, permanent magnetic field. (b) Two: a relatively strong, permanent magnetic field and a weaker, time-varying magnetic field. (c) One: a weak, time-varying magnetic field. (d) None: the Galileo spacecraft was unable to detect any magnetic field around Ganymede.
B. Two: a relatively strong, permanent magnetic field and a weaker, time-varying magnetic field.
The destruction of a large moon that ventured within Saturn's Roche limit and was subsequently destroyed explains Saturn's
ring system
If you were a tourist on Triton, Neptune's largest satellite, which of the following would likely be on your "Don't miss" list of sights to visit? (a) sulfurous volcanoes (b) tiger stripes and water jets (c) liquid hydrocarbon lakes (d) geysers of nitrogen gas
(d) geysers of nitrogen gas
The E ring of Saturn is (a) the innermost and narrowest of the rings, inside the D ring. (b) a faint, narrow ring in the Cassini division, discovered by the Galileo spacecraft. (c) between the bright, wide A ring and the faint, narrow F ring. (d) the outermost and widest of the rings, beyond the G ring.
(d) the outermost and widest of the rings, beyond the G ring.
Compare the atmospheric circulation (weather) of the four giant planets.
For both Jupiter and Saturn, convection from their internal heat sources mixes the atmosphere and promotes cloud formation. Their rapid rotation spreads out these cloud features into parallel bands that circle the planets at all latitudes. For Uranus, the circulation is also equatorial and the wind speeds are high. Since there is no convection to mix the gases and create many clouds, Uranus' atmosphere is smeared out and rather featureless. Neptune's wind speeds are much higher than its rotational speed, so the atmosphere smears out into parallel bands like Jupiter and Saturn.
Which of the gas giants has the largest icy/rocky core compared to its overall size?
From Table 11.3 Basic Properties of the Jovian Planets, we see that Neptune has the largest core, extending out to about 20,000 km from the center of the planet.
The Sun's early magnetic field interacted with nearby ionized gasses, which swept the hydrogen and helium from around the terrestrial proto-planets. We see evidence for a similar mechanism currently interacting with ionized gasses around which planet?
Jupiter
Compare the properties of Titan's atmosphere with those of Earth's atmosphere.
-Like Earth, Titan's atmosphere is primarily composed of nitrogen, but unlike Earth, one of the most abundant constituents is methane (CH4). -Titan's stratosphere indicate that its winter (northern) pole has many properties in common with Earth's: cold temperatures, strong circumpolar winds and anomalous concentrations of several compounds (on Titan, organic molecules) that are reminiscent of conditions within the winter polar regions on Earth, the so-called ozone holes. In both cases the essential ingredient is the strong winds, which isolate the polar air and inhibit mixing with that at lower latitudes.
List at least three major differences between Pluto and the terrestrial planets.
1)Pluto is much smaller than all the terrestrial planets (and even smaller than many of the big moons of the giant planets). 2)Its composition is ice and rock as opposed to the composition of rock and metal of the terrestrial planets. 3)Pluto's orbit is highly elliptical and inclined to the plane of the ecliptic as opposed to the circular orbits near the plane of the ecliptic for the terrestrial planets. 4)Pluto has a thin and variable atmosphere of nitrogen, while three of the terrestrial planets have much thicker and warmer permanent atmospheres. (Nitrogen dominates Earth's atmosphere, while carbon dioxide dominates the atmospheres of Venus and Mars. Mercury has only a very thin "temporary" atmosphere, borrowed from the solar wind.) 5)Pluto is but one object of many (including some of the same size as Pluto) in the Kuiper Belt, whereas each of the terrestrial planets dominates the mass in their respective orbits.
23. Pluto and Charon orbit their center of gravity. Where is this in relation to Pluto? A. Outside both bodies closer to Pluto B. Near the center of Charon C. Near the center of Pluto D. Outside both bodies closer to Charon E. Halfway between Pluto and Charon
A. Outside both bodies closer to Pluto
Why were the rings of Uranus not observed directly from telescopes on the ground on Earth? How were they discovered?
Additional faint dust bands and incomplete arcs may exist between the main rings. The rings are extremely dark—the Bond albedo of the rings' particles does not exceed 2%. They are probably composed of water ice with the addition of some dark radiation-processed organics. The definitive discovery of the Uranian rings was made by astronomers James L. Elliot, Edward W. Dunham, and Jessica Mink on March 10, 1977, using the Kuiper Airborne Observatory, and was serendipitous.
17. Searches for life such as SETI assume that any communicable civilizations that are found would be more technologically advanced than our own civilization. What is the basis of this assumption? A. The aliens that are being secretly held at area 51 told us that they are more advanced. B. Our civilization has only been able to communicate for about a million years. C. Any other civilizations that exist have probably been around for millions or billions of years longer than our civilization. D. The scientists think that we aren't very smart. E. The signals that SETI has already detected are too advanced for us to decode.
C. Any other civilizations that exist have probably been around for millions or billions of years longer than our civilization.
What does Jupiter's atmosphere look like? (a) A uniformly cloudy, almost featureless atmosphere in which rotational speeds are hard to discern. (b) A banded appearance with clouds in the polar region revolving around Jupiter's rotation axis in a shorter time than clouds at the equator. (c) A banded appearance with clouds in all bands taking the same length of time to revolve around Jupiter's rotation axis (solid body rotation). (d) A banded appearance with clouds at the equator revolving around Jupiter's rotation axis in a shorter time than clouds in the polar region.
D. A banded appearance with clouds at the equator revolving around Jupiter's rotation axis in a shorter time than clouds in the polar region.
20. The Kuiper belt objects are most similar in orbital characteristics and mass to A. Jupiter B. Trappist-1b C. Neptune D. Pluto E. Uranus
D. Pluto
The presence of HCN (hydrogen cyanide), a key ingredient in ________, is found on the surface of _______, indicating the possibility of life there.
DNA, Titan
18. What evidence suggests that Jupiter's inner moons formed with the planet rather than being captured from elsewhere in the solar system? A. They have orbits with very little inclination. B. They orbit in the same direction that Jupiter rotates. C. They have the same composition as Jupiter. D. All of the above. E. A and B
E. A and B
What do we call the region around a star within which planetary-mass objects (with sufficient atmospheric pressure) can have liquid water at their surfaces and possibly support life as we know it?
Habitable Zone
In some sense Jupiter could be considered to be a failed star. This is because
Jupiter has a mass nearly as large as a star & Jupiter gives off more energy than is incident upon it
Describe the solar nebula, and outline the sequence of events within the nebula that gave rise to the planetesimals.
Meteorites, comets, and asteroids are survivors of the solar nebula out of which the solar system formed. This nebula was the result of the collapse of an interstellar cloud of gas and dust, which contracted (conserving its angular momentum) to form our star, the Sun, surrounded by a thin, spinning disk of dust and vapor. Condensation in the disk led to the formation of planetesimals, which became the building blocks of the planets.
A friend of yours who has not taken astronomy sees a meteor shower (she calls it a bunch of shooting stars). The next day she confides in you that she was concerned that the stars in the Big Dipper (her favorite star pattern) might be the next ones to go. How would you put her mind at ease?
Meteors do not come from stars but from pieces of comets or asteroids that have broken off or been set free, and that enter Earth's atmosphere. Meteors are small solid objects of stone or metal, whereas stars are huge balls of hot gas and are trillions of miles away. You could also point out that meteor showers like the one she saw occur annually and yet no one has reported stars missing after any of them. The constellations (star patterns) have been observed since humans have had written history, with no reports of any disappearing
Are the planets all the same?
No, the planets differ in composition
What is the evidence for a liquid water ocean on Europa, and why is this interesting to scientists searching for extraterrestrial life?
On the outside, Europa looks like a cracked egg. This is because the exterior of the planet is made of ice that has cracked over time. Underneath the ice, there is evidence of water. There is water underneath the ice because the water is heated above freezing level from the warmth of the planet's core. Water is an element of potential extraterrestrial life. The next two elements are free energy and complex chemicals. If water exists on a planet, there may be life on the planet, or life will be formed in the future.
Describe and compare the rings of Saturn and Uranus, including their possible origins.
Saturn's rings consist of small icy objects, of average size that of a snowball. They orbit independently in a narrow band a few tens of meters thick. From Earth there appear to be three main rings, with a notable gap called the Cassini Division caused by gravitational resonance with a moon. In reality, there are several more small and/or partial rings. Uranus possesses two sets of rings. The inner system of rings consists mostly of narrow, dark rings, while an outer system of two more-distant rings, discovered by the Hubble Space Telescope, are brightly colored, one red, one blue. Scientists have now identified 13 known rings around Uranus. A 2016 study suggested the rings of Uranus, Saturn and Neptune may be the remnants of Pluto-like dwarf planets that strayed too close to the giant worlds long ago.
In the context of the giant planets and the conditions in their interiors, what is meant by "rock" and "ice"?
Scientists describe materials in these environments that are composed primarily of iron, silicon, and oxygen as "rock." Similarly, those composed of carbon, nitrogen, and oxygen in combination with hydrogen are described as "ice." The layers described in this way don't necessarily resemble rocks and ice sheets on Earth.
Give brief descriptions of both the Kuiper belt and the Oort cloud.
The Kuiper belt is a disk-shaped region of space beyond the orbit of Neptune that is dynamically stable. It is the source of short-period comets. The Oort cloud is much farther out than the Kuiper belt. It is a spherical region surrounding the Sun out to near 50,000 AU. This is the source of newly discovered long-period comets.
Which of the following is NOT a fact about the solar system that our theories of its formation must explain?
The Sun has most of the angular momentum of the solar system
The Hubble Space Telescope images of Pluto in 2002 showed a bright spot and some darker areas around it. Now that we have the close-up New Horizons images, what did the large bright region on Pluto turn out to be?
The bright spot turned out to be what has been nicknamed Sputnik Planum (the Sputnik Plains). It appears to be a bowl or sea of frozen and perhaps liquid nitrogen,much brighter and younger (no craters visible) than the darker highlands of Pluto.
How does the composition of the planets vary?
The composition of the planets varies roughly with the distance from the sun: dense metal-rich planets lie in the inner system, giant, hydrogen-rich planets lie further out
We find evidence of seasonal flows of water on Mars, but water freezes at 0 degrees Celsius and surface temperatures on Mars are on average -55 degrees C. How is this possible?
The water is very salty, which allows it to remain liquid at colder temperatures.
Explain the energy source that powers the volcanoes of Io.
Tidal flexing from Europa & Ganymede pull it into and elliptical orbit (1:2:4) in same place in orbit
Vesta is unusual as it contains what mineral on its surface? What does the presence of this material indicate?
Vesta's surface is partially covered with basalt. Basalt indicates volcanic activity at some point in Vesta's distant past, and thus that Vesta must be a differentiated world.
Saturn's E ring is broad and thin, and far from Saturn. It requires fresh particles to sustain itself. What is the source of new E-ring particles?
We now know from investigations with the Cassini mission that the new particles in the E ring are produced by the geysers on Saturn's moon Enceladus, which blasts considerable amounts of salt water ice vapor and crystals into space from the "tiger stripe" features on the moon's surface.
The largest moon in our solar system has an atmosphere that is denser than the atmosphere of Mars. The name of this moon is:
a. Titan b. Ganymede (both)
Of Jupiter's Galilean moons, the farthest out have ______________. a. the shortest orbital periods b. the most craters c. the least geologic activity d. b and c
d. b and c
The inner (Galilean) moons of Jupiter have: a. prograde orbits b. nearly circular orbits c. rock and/or ice composition d. cratered surfaces e. all of the above
e. all of the above
The event which we think triggered the gravitational collapse that led to the formation of the solar system, according to our best theoretical model, was a
nearby supernova
The ring system of the gas giant planets most probably result from
the movement of an object within each planet's Roche limit, where tidal forces ripped it apart
The mass of Jupiter is about
twice that of all the other planets combined
Why is it difficult to drop a probe like Galileo? How did engineers solve this problem?
Aside from having to engineer the craft to survive the magnetosphere of Jupiter, the high speeds involved would guarantee that the probe would burn up on entering the atmosphere. The problem was solved using a heat shield in front of the spacecraft to absorb the heat. After the probe had slowed down, the heat shield was jettisoned and the parachute was deployed, further slowing the probe.
2. Neptune's existence was uniquely predicted before it was ever observed. What evidence was this prediction based on? A. Neptune is located at the next distance from the Sun dictated by Bode's law. B. A gravitational force due to Neptune was invoked to explain observed irregularities in Uranus' orbit. C. The leading Solar System formation theory of the time required Neptune to account for the"missing mass." D. Neptune was invoked to explain the orbit of Triton E. None of the above.
B. A gravitational force due to Neptune was invoked to explain observed irregularities in Uranus' orbit.
Jupiter and Saturn are mostly liquid hydrogen. How (if at all) do the interiors of Uranus and Neptune differ from this? (a) Other than size—Uranus and Neptune being smaller than Jupiter and Saturn—there is no significant difference among the four planets. (b) Uranus and Neptune have a much thicker layer of water outside the rocky core, as well as a much thinner mantle of liquid hydrogen mantle. (c) Uranus and Neptune have a deep mantle of liquid methane and ammonia outside the rocky core, which Jupiter and Saturn do not have; Uranus and Neptune are not massive enough to have liquid hydrogen. (d) The rocky cores of Uranus and Neptune take up most of the planet, with only a relatively thin mantle of water and liquid hydrogen.
B. Uranus and Neptune have a much thicker layer of water outside the rocky core, as well as a much thinner mantle of liquid hydrogen mantle.
One significant physical characteristic of the high-pressure form of hydrogen that is thought to exist in the interior of Jupiter is that it (a) is a crystalline solid, making up the core and interior of Jupiter. (b) is dark red in color; it is this hydrogen that we are seeing through gaps between the clouds, in Jupiter's belts. (c) is an electrically conducting liquid. (d) remains gaseous all the way to the central, icy ocean, despite the immense pressure at these depths.
C. is an electrically conducting liquid
How was Pluto discovered? Why did it take so long to find it?
Although the discovery of Neptune rang the death knell for one proposed law of physics, it cemented the status of Newton's law of gravity as paramount. In addition, the method by which Neptune was discovered clearly suggested that the same method could be used to predict the existence and location of the next planet. All we have to do is observe the location of Neptune over a period of years, note the discrepancies between the observed and predicted positions, and use those discrepancies to determine the mass and location of the 9th planet. In 1848, J. Babinet made the first such prediction of a planet with a mass 12 times that of the Earth. Note that at this time, Neptune, which has an orbital period of 165 years, had only moved about 4 degrees in the sky, out of one 360 orbit, and even today has not yet completed one orbit around the Sun since it was discovered!
We find strong clues from several solar system objects that they may harbor some forms of life. These worlds are
Earth, Mars, Europa, Titan, Triton
How are comets related to meteor showers?
Comets are the origin of meteors. As a comets and its debris surrounding it move across the sky in it's cycle, Meteors are in contact with its path and they will rain down from its source, it's comet.
Describe the origin and eventual fate of the comets we see from Earth.
Comets that "fall" into the inner solar system were once located either in the Oort cloud about 50,000 AU from the Sun or the Kuiper belt. The Oort cloud is far enough away that the gravitational influence of passing stars can perturb a comet's orbit. Some perturbations can send a comet out into interstellar space never to return. But others can send the comet nucleus inward toward the Sun; it is these comets that occasionally dazzle us here on our planet. Kuiper belt chunks can be perturbed by interactions with Neptune. A comet headed toward the inner solar system could hit the Sun or impact a planet. Or it could be "caught" by an interaction with one of the giant planets to become a really short-period comet. A comet trapped in the inner solar system will have a lifespan of just a few thousand orbits before it collides with a planet or all the volatiles escape, making it a "dead" comet.
Describe the two types of comet tails and how each are formed.
Comets typically have both a dust tail and an ion tail. The dust tail is larger and brighter than the ion tail and is formed by the action of sunlight imparting energy to the dust particles and pushing them away gently from the nucleus. The ion tail is composed of charged particles and are pushed away by the streams of charged particles emanating from the Sun (the solar wind). The dust tail tends to curve as the particles go into orbit around the Sun, whereas the ion tail tends to be straighter as the charged particles are pushed in the direction that is away from the Sun.
In what ways are meteorites different from meteors? What is the probable origin of each?
Meteors that reach Earths atmosphere originate from comets, or the dust that is left from a comet. Meteorites do not come from comets. many meteorites are fragments from the breakup in the atmosphere of a single larger object meteorites hit earth but most meteors that enter our atmosphere do not survive the trip.
Would you expect to find more impact craters on Io or Callisto? Why?
More on Callisto. Io is so volcanically active, it erases or covers over all impact craters in a very short period of time. Also, the surface is likely to soft to hold the imprint of a crater for long. Callisto, on the other hand is frozen solid with no heat sources. Like the Moon, it should preserve a record of its cratering history for the full history of the solar system.
What evidence do we have for the existence of the Kuiper belt? What kind of objects are found there?
Over a thousand members of the Kuiper belt have been found directly in recent years, including dwarf planets Pluto, Eris, and Make make. The size and numbers of these icy objects suggest that many additional smaller bodies must also exist in the same region, in a disk extending out to about 50 AU from the sun.
How are Triton and Pluto similar?
The interiors of both Pluto and Triton are likely composed primarily of water ice over a rocky core, and in roughly similar amounts. Both are a little bit smaller than our own moon (Triton's diameter is 2,700 kilometers, Pluto's is about 2,230 km). Their outer layers also have some amount of non-water ices such as methane, carbon dioxide and nitrogen, which are present on their surfaces and their thin atmospheres of nitrogen, methane and other minor gases replenished from sublimation of ices from their surfaces. Because Pluto's composition is likely similar to Triton's, some of the features we see on Triton (such as the "cantaloupe terrain" and wind streaks shown in the figures above) may also exist on Pluto. The dark wind streaks detected by Voyager 2 on Triton's surface were tens to hundreds of kilometers long and preferentially pointed northeast, away from the south pole.
Why do meteors in a meteor shower appear to come from just one point in the sky?
This illusion is an effect of perspective, just as a roadway seems to converge in the distance. Usually, meteor showers take the name of the constellation from which the meteors appear to radiate.
Which planet seems to be turned on its side with an axis tilt of 98 degrees?
Uranus
Which gas giant do we suspect may have a rocky core? a. Jupiter b. Saturn c. Neptune d. Uranus e. all of the above
e. all of the above
Jupiter's atmosphere has high- and low-pressure burnt orange and white bands that wrap completely around the planet. This is caused by Jupiter's
rapid rotation
21. What was the microbe capable of living in space that we mentioned in class? A. Deinococcus radiodurans (conan the bacterium) B. Helicobacter pylori C. cyanobacteria D. The cold virus
A. Deinococcus radiodurans (conan the bacterium)
12. Scientists are interested in searching for life on: A. Mars, Jupiter, Earth's moon B. Mars, Venus, Asteroid belt C. Mars, Europa, Titan, Triton D. Mars, Venus, Jupiter E. Mars, Europa, Venus
C. Mars, Europa, Titan, Triton
Why (except for its spectacular rings) does Saturn appear relatively featureless compared to Jupiter? (a) Saturn rotates more slowly than does Jupiter, and its circulation pattern is not stretched around the planet as on Jupiter. (b) Saturn is farther from the Sun, and it does not receive enough heat from the Sun to create major circulation patterns. (c) Saturn's atmosphere is clear, and we are seeing the top of the featureless liquid hydrogen ocean. (d) Saturn has belts, zones, and storms similar to those of Jupiter, but they are obscured by haze in the upper atmosphere.
D. Saturn has belts, zones and storms similar to those of Jupiter, but they are obscured by haze in the upper atmosphere.
9. What evidence suggests that all of the planets formed from a disk around the Sun? A. They have orbits with relatively little inclination. B. They have the same composition as the Sun. C. They orbit in the same direction that Sun rotates. D. All of the above. E. A and B
E. A and B
What do scientists find most interesting about methane on Titan?
Methane exists at the triple point - as a solid, liquid and gas - on its surface.
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.
T/F Meteorites differ in chemical and geological properties from all known planetary and lunar rocks
True
Meteors are the result of the Earth's atmosphere sweeping up small debris in space. Most of this debris resulted from
the destruction of asteroids and comets
The planet Jupiter consists mostly of (a) methane and ammonia gases and water vapor. (b) hydrogen. (c) rocks and minerals, similar to Earth. (d) liquid water, methane, and ammonia.
(b) hydrogen.
Which planet has the strongest magnetic field, and hence the largest magnetosphere? What is its source?
-Some 20,000xs stronger than Earth's, Jupiter's magnetic field cr8s a magnetosphere so large it begins to avert the solar wind almost 3 mil kms before it reaches Jupiter. The magnetosphere extends so far past Jupiter it sweeps the solar wind as far as the orbit of Saturn. Like Earth's magnetosphere, many of the charged particles trapped in Jupiter's magnetosphere come from the solar wind; however, Jupiter has an extra source of particles that other planets do not have. Jupiter's volcanically active moon, Io, provides a substantial portion of charged particles to Jupiter's magnetosphere. These charged particles can spiral along the planetary magnetic field lines into the upper atmosphere and around the magnetic poles. When these energetic particles, usually electrons, collide with atoms and molecules in the atmosphere they transfer energy. This energy is then released, sometimes in the form of visible light. This is the same process that produces the different colored auroras we see on Earth. Jupiter also has auroras on its north and south poles. Io and the other Galilean moons are affected by Jupiter's magnetosphere. The charged particles trapped around the planet occasionally hit the surfaces of the moons, releasing some atoms and molecules which sometimes create a thin atmosphere around the moon.
What are the main challenges involved in sending probes to the giant planets?
1.Giant planets are solely made up of gas, hence there is no surface to land the probes on. 2. Due too crazy atmosphere on these planets, the probes would most likely get destroyed once they hit the atmosphere of the planets 3. Very costly to send probes to the Giants. 4. The huge distances that require many years of flight time. The spacecraft must be reliable and robust to survive the journey. 5. The low temperatures of space require onboard heating so the components don't freeze. 6.The light levels = too low for solar panels to provide enough energy, requiring onboard power systems. 7. Transmitters must be powerful enough to communicate with Earth over the vast distances of space. 8. At low light levels, photographs require longer exposures; however, fast-moving spacecraft will change position during these times and smear the image unless the arm with the camera moves backward at the same rate that the spacecraft moves forward.
Which Planets rotates in a retrograde motion instead of the normal prograde motion which all other planets and the sun rotate in?
Venus and Uranus
11. The Drake equation to estimate the number of intelligent civilizations in the Milky Way predicts: A. Intelligent life is very uncommon B. Intelligent life is very common C. Intelligent life is decently common
A. Intelligent life is very uncommon
14. Jupiter's rotation axis is tilted by 3 degrees. This results in: A. No seasons at all B. Very long seasons C. Short days D. Large seasonal storms E. Large magnetic fields
A. No seasons at all
What is surprising about the magnetic fields of Uranus and Neptune? (a) They are tilted at a large angle to the spin axis, and they are offset from the centers of the planets. (b) That they exist at all: neither Uranus nor Neptune is expected to have a molten metallic core like that of the Earth. (c) They are aligned almost precisely along the spin axis of each planet, unlike the Earth, where the magnetic poles are angled about 10° away from the spin axis. (d) They vary in strength and orientation on timescales of only a few years.
A. They are tilted at a large angle to the spin axis, and they are offset from the centers of the planets.
What is the basic structure of Jupiter's interior? (a) a small, rocky core surrounded by a layer of liquid "ices" and an immense layer of helium and liquid hydrogen outside that (b) a uniform liquid composed almost entirely of hydrogen and helium, with traces of icy and rocky material (c) rock throughout most of the interior, surrounded by a thin layer of helium, liquid hydrogen, and liquid "ices" (d) an immense ocean of liquid "ices," with a small, rocky core and a thin atmosphere consisting mostly of hydrogen and helium
A. a small, rocky core surrounded by a layer of liquid "ices" and an immense layer of helium and liquid hydrogen outside that
25. Bode's law is called an empirical law because A. it describes an observed phenomenon without providing any underlying theoretical explanation for why the Solar System seems to work that way B. it follows directly from Kepler's empirical laws C. it correctly predicted the existence of Neptune before the planet was ever observed D. it is based solely on a theoretical understanding of the Solar System E. the emperor in Bode's time decreed it to be true
A. it describes an observed phenomenon without providing any underlying theoretical explanation for why the Solar System seems to work that way
22. We have seen that water can act like lava on a few bodies in our solar system. Which of the following does this imply? A. Water can glow red hot in space because of the lack of atmosphere. B. Heated water becomes a hot liquid and moves through frozen water. If it is acting like lava, then the materials around it are very cold comparatively. C. Water in space can become as hot as molten rock on Earth because it's in a vacuum. D. Water is rare on those bodies like lava is rare on Earth.
B. Heated water becomes a hot liquid and moves through frozen water. If it is acting like lava, then the materials around it are very cold comparatively.
Dark spokes that are visible in Saturn's rings are believed to be caused by (a) orbital resonances with Saturn's large satellites. (b) interaction of dust in the rings with Saturn's magnetosphere. (c) small, shepherding satellites within the rings. (d) electrical discharges in the differentially rotating rings.
B. Interaction of dust in the rings with Saturn's magnetosphere.
8. What explanation is given for the different composition of Neptune compared to Jupiter? A. Neptune formed in a part of the solar nebula with less metallic Hydrogen B. Jupiter happened to become more massive and kept getting bigger because of its stronger gravity. C. Jupiter formed somewhere else and was captured by the Sun. D. Neptune formed in a part of the solar nebula with less Hydrogen E. None of the above.
B. Jupiter happened to become more massive and kept getting bigger because of its stronger gravity.
3. Which of the following statements about the solar system are true? A. Every planet obeys Bode's law exactly. B. More massive planets tend to have significant amounts of hydrogen compared to less massive planets C. Most planets rotate slowly, about once per orbit. D. The planets contain as much mass as the Sun. E. All of the above.
B. More massive planets tend to have significant amounts of hydrogen compared to less massive planets
24. Why is a body like Neptune very nearly spherical while an asteroid is not? A. Neptune is farther away from the Sun, so less sunlight reaches its surface per unit area. B. Neptune has enough self-gravity to make it spherical due to its mass. C. Asteroids don't have atmospheres. D. Asteroids are not yet fully formed. E. Neptune has rings.
B. Neptune has enough self-gravity to make it spherical due to its mass.
Which planets in our solar system are known to have rings around them? (a) only Saturn (b) all of the giant outer planets: Jupiter, Saturn, Uranus, and Neptune (c) only Saturn (wide, bright rings) and Uranus (narrow, dark rings) (d) only the most massive: Jupiter and Saturn
B. all of the other outer planets: Jupiter, Saturn, Uranus, and Neptune
What is the one observation of Triton, the giant moon of Neptune, that seems to indicate that it was captured by the gravity of the planet rather than being formed as part of the Neptune system? (a) It is irregular in shape and dark in color. (b) It has a fractured surface with many deep impact basins. (c) It orbits in a retrograde direction, opposite to the planet's rotation. (d) Its overall composition, consisting mostly of rock with only a thin, icy mantle, is more characteristic of parts of the solar system closer to the Sun.
C. It orbits in a retrograde direction, opposite to the planet's rotation.
After the Galileo spacecraft reached Jupiter, it dropped a probe on a parachute into Jupiter's atmosphere, which is mostly hydrogen. As this probe descended deeper and deeper into Jupiter's interior, what would it have encountered? (a) The atmospheric pressure would have gradually increased until the probe splashed onto the surface of an immense, liquid-hydrogen ocean. (b) The probe would have fallen through a deep, gaseous atmosphere of greatly increasing pressure until it finally landed on the surface of a hard, rocky core. (c) The atmospheric gases would have become denser and denser until they were dense enough to be called a liquid, without any distinct boundary or "surface" at all. (d) Jupiter is entirely a gas, and the probe would have fallen to the center of the planet, where it remains today.
C. The atmospheric gases would have become denser and denser until they were dense enough to be called a liquid, without any distinct boundary or "surface" at all.
What is believed to be the reason why Neptune's satellite, Triton, is slowly spiraling in toward Neptune, eventually to collide with it or be pulled apart to form a ring system? (a) Triton has a dense atmosphere and ionosphere, and the magnetic field of Neptune creates strong electric currents in the ionosphere that rob the moon of energy. (b) Triton orbits faster than the other satellites, so it is being gravitationally slowed by them. (c) Triton's retrograde orbit results in tidal disturbances on Neptune that act against Triton's motion. (d) Neptune's tenuous outer atmosphere is exerting a drag force on Triton that is slowly robbing the moon of energy.
C. Triton's retrograde orbit results in tidal disturbances on Neptune that act against Triton's motion.
7. Why does Saturn have rings? A. The momentum of the material prevents it from falling onto the planet. B. Tides and collisions prevent the material from coalescing into a moon. C. The combination of angular momentum and collisions between particles result in a disk. D. All of the above. E. C and B
D. All of the above.
16. Our theory of the origin and evolution of the solar system cannot account for which fact about the solar system? A. the direction of rotation of most of the planets B. The composition of the planets varying with distance from the Sun. C. the Sun's mass in relation to the mass of the planets D. Bode's law E. the nearly circular orbits of the planets
D. Bode's law
1. Where did the atmosphere of the Earth come from? A. Capturing the solar wind. B. If formed as gasses that were captured during the formation of Earth. C. Comets crashing to Earth brought the gasses. D. Methane and other gasses emitted by life. E. Outgassing of volatile molecules from the interior of the Earth after the formation.
E. Outgassing of volatile molecules from the interior of the Earth after the formation.
10. Why don't the rings of Jupiter form a new moon? A. Because Jupiter has no rings. B. There is no gravity in the rings. C. The dust and ice in the rings are too cold to form a moon. D. There is no rocky material in the rings with which to form a moon. E. The rings lie within the Roche limit, preventing anything big like a moon from forming.
E. The rings lie within the Roche limit, preventing anything big like a moon from forming.
13. The Drake equation can be used to estimate the number of intelligent civilizations in our Galaxy. Which of the following is NOT a factor in the Drake Equation? A. Rate of formation of stars in our Galaxy B. Fraction of stars with a planetary system. C. Fraction of planets with life on which intelligent life emerges. D. Average number of planetary environments suitable for life in a planetary system. E. Typical "doubling" timescale of an intelligent civilization's computing power.
E. Typical "doubling" timescale of an intelligent civilization's computing power.
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. Jupiter has the largest internal energy source, about the same as the total solar energy absorbed by Jupiter. Most of the internal energy of Jupiter is primordial heat, left over from the formation of the planet 4.5 billon years ago. Saturn has an internal energy source about half as large as Jupiter's; since its mass is only about one quarter as great, this means that it is producing twice as much energy per unit mass of material as does Jupiter. The source of this energy is the separation of helium from hydrogen in Saturn's interior. In the liquid hydrogen mantle, the heavier helium forms droplets that sink toward the core, releasing gravitational energy. In effect, Saturn is still differentiating—letting lighter material rise and heavier material fall. Uranus and Neptune are different. Neptune has a small internal energy source, while Uranus does not emit a measurable amount of internal heat.
Describe the seasons on the planet Uranus.
From Exercise 5 we know the planet is "on its side." Each pole experiences a 21-year sunlit "summer" and later a 21-year dark "winter." For the other half of the "Uranus year," the equator receives the light of the Sun and each hemisphere experiences what we would call a normal "day." In all, each pole experiences 42 years of light and 42 years of dark during its 84-year-long orbit.
Would you expect to find free oxygen gas in the atmospheres of the giant planets? Why or why not?
In the early solar system, most of the oxygen combined with hydrogen to make H2O and was thus unavailable to form the kinds of oxidized compounds with other elements that are more familiar to us in the inner solar system (such as CO2). As a result, the compounds detected in the atmosphere of the giant planets are mostly hydrogen-based gases such as methane (CH4) and ammonia (NH3), or more complex hydrocarbons (combinations of hydrogen and carbon) such as ethane (C2H6) and acetylene (C2H2).
What is the primary source of Jupiter's internal heat?
Most of the internal energy of Jupiter is primordial heat, left over from the formation of the planet 4.5 billon years ago, when it gathered together from smaller "planetesimals" and accreted gas; the gravitational energy lost as these "building blocks" fell together turned into heat.
What direction do most planets in the solar system revolve around?
Most planets revolve around the Sun in the prograde sense-the same direction the Sun rotates (west-east)
Why do the upper levels of Neptune's atmosphere appear blue?
Neptune's atmosphere is made up of hydrogen, helium and methane. The methane in Neptune's upper atmosphere absorbs the red light from the sun but reflects the blue light from the Sun back into space. This is why Neptune appears blue.
How did the giant planets grow to be so large?
Outside the frost line, temperatures are cooler and hydrogen compounds are able to condense into ices. Rock and metal are still present in the outer solar system, but both are outnumbered and outweighed by the hydrogen compounds. Thus, the planetesimals that formed in the outer solar system are composed primarily of hydrogen compounds with traces of rock and metal. Hydrogen and helium do not condense in the solar nebula, and are rather abundant in the large orbits of objects in the outer solar system. As the outer planetesimals continued to grow larger, the strength of their gravity grew stronger. Surrounding material, primarily hydrogen and helium, is increasingly attracted to the planetesimals as they grow in size and the planetesimals accrete more and more. The jovian planetesimals soon became the icy, dense cores we see today surrounded by huge clouds of accreted gas. Much like the collapse of the solar nebula, these balls of gas can grow large enough to induce gravitational collapse. Remember from the star formation section that gravitational collapse involves heating up, flattening out and rotating faster. It is possible that as the jovian protoplanets collapsed, smaller particles in the surrounding disk formed into some of the moons that now orbit the individual outer planets. This makes sense, since the outer planets all have many moons and rings that orbit in the same plane, just like the planets in our solar system orbit the Sun in the same plane.
How do storms on Jupiter differ from storm systems on Earth?
Storms on Jupiter can last much longer than they do on Earth because they have a continuous source of energy. On Earth, hurricanes form when water evaporates from warm oceans and rises into the air as water vapor. As the vapor rises and cools, it condenses to form clouds and precipitation, a process that releases heat which further drives the evaporation process. Storms feed off of this evaporation and condensation loop but they lose strength when their source of energy and the evaporation lessens, such as when they hit land. On Jupiter, storms can last a very long time because there is no land and weather is driven largely by the consistent internal heat of the planet. This is different from Earth's weather, which is fueled by solar energy heating the Earth.
What are the visible clouds on the four giant planets composed of, and why are they different from each other?
The clouds of Jupiter and Saturn are primarily crystals of frozen ammonia. On Uranus and Neptune, the clouds are composed of methane. The temperatures of these worlds 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 differences in the chemical makeup of the inner and outer parts of the solar system. What is the relationship between what the planets are made of and the temperature where they formed?
The inner planets are made up of rock and metal and are therefore solid. These planets move slowly as they are considered to be heavy. They have an average diameter of about 13000 km as they are small planets. On the other hand, the outer planets are said to be made of gases and they are not really solid. The gases which make them up are Hydrogen and Helium; huge balloons floating in the space are considered as giant gas planets by people and they have an average diameter of about 48000 km. Furthermore, the inner planets are warmer than outer planets simply due to the fact that they are closer to the Sun. Outer planets are composed of lighter elements such as gases and inner planets are composed of heavy elements such as iron. Inner planets have fewer moons, small, silicate surface, nickel-iron core, higher density and rotate more slowly compared to outer planets. Outer planets have a greater number of moons, no solid part; rotate faster, have a lower density as well as rings in some cases (Jupiter and Saturn). Outer planets are significantly bigger than the inner planets as Jupiter is measured to be 88846 miles in diameter and Mercury is measured to be 3031 miles in diameter.
What are the seasons like on Jupiter?
The spin axis of Jupiter is tilted by only 3°, so there are no seasons to speak of.
What is the consequence of Uranus' spin axis being 98° away from perpendicular to its orbital plane?
This essentially means that Uranus is on its side, with the poles alternately facing toward and away from the Sun. Each pole experiences long periods of light and darkness. The seasons alternate between half the planet being in the light and half in darkness for one season, to the planet's axis being sideways to the Sun and its rotation causing regular alternation of light and dark for the next season.