Unit 3 Chpt 13 Uranus & Neptune

The discovery of new planets mostly requires

The patient use of improving technology

Uranus was discovered about the same time as

the U.S. Declaration of Independence;

Compared with Uranus, the planet Neptune is

roughly the same size;

The jovian planets with the largest diameters also tend to

have magnetic field axes most closely aligned with their axes of rotation.

The five largest moons of Uranus

all orbit directly above the planet’s equator;

Moons that show few craters probably

have warm interiors.

A gas giant planet orbiting a distant star would be expected to have

evidence for hydrogen in its spectrum.

Uranus’s rings were discovered by the occultation of starlight, as shown in Figure 13.15 (“Occultation of Starlight”). If Uranus were moving more rapidly relative to Earth, the graph in that figure would appear

more compressed horizontally;

The discovery of a moon orbiting a planet allows astronomers to measure

the planet’s mass;

The solar system object most similar to Neptune is

Uranus

Why did astronomers suspect there was an eighth planet beyond Uranus?

Irregularities in the motion of Uranus suggested that gravity from another planet was affecting it.

In 1781, Uranus was the first new planet to be discovered in how many years?

more than 2000

What was the first planet discovered by mathematical prediction?

Neptune

Why weren't the outermost planets discovered until after the invention of the telescope?

They were too faint to be observed with the unaided eye

The extreme seasonal variations on Uranus over the course of a complete orbit around the Sun are due to which of the following?

the 98° tilt of its rotation axis to its orbital plane

Which planet has the greatest tilt of its rotation axis?

Uranus

From Wien's law, at what wavelength does Uranus's thermal emission peak?

5.0×10⁴

In what part of the electromagnetic (5.0×10⁴) spectrum does this wavelength lie? (More Precisely 3-2)

infrared

Why is Neptune bluer than Uranus?

It has more methane.

What is the most significant difference between the Great Dark Spot of Neptune and the Great Red Spot of Jupiter?

The Great Dark Spot has disappeared, whereas the Great Red Spot has been seen for hundreds of years.

What substance is responsible for the colors of Neptune and Uranus?

methane

What outstanding questions about the interiors, moons, and rings of Uranus and Neptune might be answered by a dedicated space mission such as Cassini or Juno?

reasons of difference between outward appearances of the planets; if Neptune’s ring system is only a transient situation, or the system’s “normal” structure; 
if Uranus’ moons have undergone disruptions as Miranda apparently has; how much and how quickly their magnetic fields are changing; 
investigation of Triton’s geysers

Which of the following statements is NOT true about the magnetic fields of Uranus and Neptune?

They are stronger than the magnetic field of Jupiter.

As a percentage of their total volumes, how do the cores of Uranus and Neptune compare with those of Saturn and Jupiter?

Their cores are larger than those of Jupiter and Saturn.

What has created Uranus's magnetic field?

a layer of conducting water

What evidence suggests that Triton is a captured moon?

It has a retrograde, highly inclined orbit.

It has a retrograde, highly inclined orbit.

It has been catastrophically disrupted and reassembled several times.

Why are the moons of Uranus and Neptune so dark?

They are subject to radiation darkening.

A gas giant planet orbiting a distant star would be expected to have

evidence for hydrogen in its spectrum.

All but one of the following properties of Uranus's rings makes them different from the rings of Saturn. Which property is the same for both planets?

They are very thin.

On which planet can the pole remain in darkness for 42 years, and then have 42 years of constant daylight?

Uranus

Studying the magnetospheres of the jovians has allowed us to measure their:

rotation rates

A day at the north pole of Uranus lasts:

about 42 years.

The axial tilts of Uranus and Neptune are similar.

False

The unique feature of Neptune is:

that its atmosphere rotates more slowly than its interior

Neptune has a larger fraction of methane in its atmosphere than Uranus.

True

In strength, the magnetic fields of Uranus and Neptune are:

similar, with both about 100 times stronger than our own.

The rings of Uranus and Neptune are found:

above their equators