Astronomy 1010 Exam #2 Chapter 10

Uranus's orbit did not appear to behave according to Newton's laws of motion and gravity. The most likely culprit for Uranus's misbehaving orbit was the gravitational influence of another planet. Using Newton's laws, astronomers were able to calculate exactly where they would expect this still-undiscovered planet to be. When telescopes were pointed at this position, Neptune was seen. What does this imply? Choose one: A. Newton's laws have been verified by yet another test, so we should use them with high confidence until and unless they are falsified by future tests. B. Newton's laws have been verified by yet another test, but there is still not enough evidence for them, so they should be treated with cautious skepticism. C. Newton's laws have been falsified. D. Newton's laws have been verified as absolute truth.

A. Newton's laws have been verified by yet another test, so we should use them with high confidence until and unless they are falsified by future tests.

The colored bands of Jupiter and Saturn are due in part to their compositions: Water and ammonia clouds reflect white light, and ammonium hydrosulfide clouds reflect brown and red light. Alternating cells of rising and falling air can bring ammonia to higher altitudes, where it can condense into visible clouds, or they can push the air down into lower altitudes, making the deeper ammonium hydrosulfide cloud layer visible. The bands of Jupiter are more obvious than those of Saturn, with brighter and more highly varying colors. Compare the cloud layers of Jupiter and Saturn shown to determine why. Choose one: A. Saturn's different cloud layers are deeper, making them harder to see. B. Jupiter only appears to have brighter bands than Saturn because it is closer to us. C. Jupiter has a thicker ammonium hydrosulfide layer, so it will produce more vibrant browns and reds. D. Jupiter has a greater variety of materials in its clouds, making it more colorful.

A. Saturn's different cloud layers are deeper, making them harder to see.

Why do Jupiter and Saturn appear red/white and brownish orange, while Uranus and Neptune are blue? From the following figures displaying the composition of the Jovian planets with depth, choose the most likely reason for this difference. Note that we are looking at/through the upper cloud layers of each planet, which gives us the perception of a visible surface. Labels of "ice" in the figure refer to clouds made of tiny ice crystals, not a solid layer of ice. Choose one: A. The cloud tops of Jupiter and Saturn have a different composition from the cloud tops of Uranus and Neptune. B. Uranus and Neptune are much colder than Jupiter and Saturn, so their blackbody spectrums will peak in the blue. C. Uranus and Neptune are much smaller than Jupiter and Saturn, so we are seeing closer to their icy blue cores.

A. The cloud tops of Jupiter and Saturn have a different composition from the cloud tops of Uranus and Neptune.

Which of the giant planets has the most extreme seasons? Choose one: A. Uranus B. Neptune C. Jupiter D. Saturn

A. Uranus

Individual cloud layers in the giant planets have different compositions. This happens because Choose one: A. different volatiles freeze out at different temperatures. B. the Coriolis effect only occurs close to the "surface" of the inner core. C. the winds are all in the outermost layer. D. there is no convection on the giant planets.

A. different volatiles freeze out at different temperatures.

Once all the giant planets were discovered, scientists could compare their properties to learn something about them. Study this picture, and choose the following options that match your observations. Choose one or more: A. All of the planets have bands of alternating colors. B. Some planets differ considerably in color from one another. C. The planets all have similar colors to one another. D. The planets range from having very distinct feature details with a variety of colors to being completely featureless and monochrome.

B. Some planets differ considerably in color from one another. D. The planets range from having very distinct feature details with a variety of colors to being completely featureless and monochrome.

Jupiter and Saturn, despite being considerably farther from us than the inner terrestrial planets, are very bright in our sky. Which of the following choices are possible explanations for this? Choose one or more: A. Dust obscures our view of the inner planets more than the outer ones. B. They are more reflective (higher albedo) than most of the terrestrial planets. C. Since they are closer to stars, more starlight is reflected off of them than the inner planets. D. They are larger than the terrestrial planets. E. They are so hot that they emit blackbody radiation that peaks in the visible.

B. They are more reflective (higher albedo) than most of the terrestrial planets. D. They are larger than the terrestrial planets.

Why is Jupiter reddish in color? Choose one: A. because it is moving away from Earth very quickly B. because of the composition of its atmosphere C. because it is rusty, like Mars D. because it is very hot

B. because of the composition of its atmosphere

Deep in the interiors of the giant planets, water is still a liquid even though the temperatures are tens of thousands of degrees above the boiling point of water. This can happen because Choose one: A. the outer Solar System is so cold. B. the pressure inside the giant planet is so high. C. space has very low pressure. D. the density inside the giant planet is so high.

B. the pressure inside the giant planet is so high.

Uranus is visible to the naked eye, a bit brighter than the faintest naked-eye stars. However, it was not until well after the invention of the telescope in the late 18th century that Uranus was accidently discovered. How could people have missed this naked-eye planet until then? Compare Uranus's properties in the following chart to the other planets, then select the option that could explain why Uranus was harder to discover. Choose one: A. None of the listed properties should have any effect on its ease of discovery. B. It has a longer rotation period than Jupiter and Saturn. C. It has a longer orbital period than Jupiter and Saturn. D. Its rotation axis is tilted nearly on its side (high obliquity).

C. It has a longer orbital period than Jupiter and Saturn.

Why has the Great Red Spot been seen for only 400 years? Choose one: A. Prior to 400 years ago, that side of Jupiter faced away from Earth. B. The spot began 400 years ago. C. It was 400 years ago that Jupiter was first examined through a telescope. D. The planet Jupiter was discovered 400 years ago.

C. It was 400 years ago that Jupiter was first examined through a telescope.

Why do Jupiter and Saturn have no blue methane cloud tops? Choose one: A. Methane can only condense deeper inside the planets, but the upper layers obstruct our view of it. B. There was no methane in the solar nebula at the location where Jupiter and Saturn formed. C. They are too warm for methane to condense. D. They are too cold for methane to condense.

C. They are too warm for methane to condense.

How do astronomers measure the size of the Great Red Spot? Choose one: A. They send spacecraft to the top of the spot to physically measure the size of it. B. They use the Doppler shift in reflected light from the cloud tops. C. They compare its dimensions to the known diameter of Jupiter. D. They time the spot as it makes a rotation around the planet.

C. They compare its dimensions to the known diameter of Jupiter.

The following image shows the southern auroras of Saturn in green. What causes the auroras of the giant planets? Choose one or more: A. strong electrical currents B. tilted magnetic fields C. charged particles D. strong magnetic fields

C. charged particles D. strong magnetic fields

Methane gas absorbs red light, and methane clouds reflect blue light, giving Uranus and Neptune their distinctive blue colors. Why do Uranus and Neptune have methane clouds, but Jupiter and Saturn do not? Study the red curves in the following figures to determine which factor most likely plays a role in the composition of each planet's cloud tops. Choose one: A. density B. diameter of the planet C. temperature D. altitude

C. temperature

Stellar occultations are the most accurate way to measure the _________ of a Solar System object. Choose one: A. density B. mass C. temperature D. diameter

C. temperature

After it was discovered, astronomers predicted Uranus's orbit using Newton's laws of motion and gravity, which had worked extremely well for all of the other planets. To their surprise, they found that their observations of Uranus's motion through the sky did not match their predictions. Which of the following would be the most logical next step? Choose one: A. Newton's laws of motion and gravity have been falsified, so they should be scrapped in favor of a completely new hypothesis. B. If the data doesn't match Newton's laws of motion and gravity, then the data must be bad, so this finding should be disregarded. C. Newton's laws of motion and gravity must be modified to match the data. D. Check for other previously undiscovered factors that might alter Uranus's orbit while still allowing it to obey Newton's laws of motion and gravity.

D. Check for other previously undiscovered factors that might alter Uranus's orbit while still allowing it to obey Newton's laws of motion and gravity.

When viewed through a telescope, Uranus and Neptune are distinctly bluish green in color. What gas is responsible for this striking appearance? Choose one: A. water B. hydrogen C. helium D. methane

D. methane

Zonal winds on the giant planets are stronger than those on the terrestrial planets because Choose one: A. the moons of the giant planets provide additional pull. B. the moons of a giant planet feed energy to their planet through the magnetosphere. C. the giant planets have more thermal energy. D. the giant planets rotate faster.

D. the giant planets rotate faster.

Different materials condense into clouds at different temperatures, as shown in these plots of the temperatures of the cloud layers of Jupiter and Uranus. Use the temperature curves shown to rank the following cloud types in order of decreasing temperature.

Highest temperature Water ice Ammonium hydrosulfide ice Ammonia ice Hydrogen sulfide ice Methane ice Lowest temperature

Place these volatiles in order of the temperatures at which each will condense to form a cloud layer on one of the four Jovian planets.

Lowest temperature Methane ice Ammonia ice Ammonium hydrosulfide ice Water ice Ammonia droplets Highest temperature

Place in order of diameter the following types of extrasolar planets.

largest puffy Jupiters super-Jupiters mini-Neptunes super-Earths smallest