Compared to the terrestrial planets, the gas giants have,

Fast rotation and strong magnetic fields.

What is the ratio of the total number of moons of the gas giants to the total number of moons of the terrestrial planets (approximately)?


The density of the gas giants is similar to that of which substance (compare to the properties the substance has when it is on the Earth's surface at standard temperature and pressure)?


Which is true about the interiors of the gas giants?

They have gaseous outer layers, liquid inner layers and a core of denser material.

Which best describes the history of space mission to the gas giants?

Jupiter and Saturn have been visited by orbiters, Uranus and Neptune only by fly-by missions.

What can we learn about Jupiter by observing its rotation?

a. The equator is rotating faster then the poles.
b. Jupiter has the fastest spin of any planet.
c. Jupiter has a dense compact core.

What makes up most of Jupiter's atmosphere?
: What makes up most of Jupiter's clouds?

. Hydrogen and helium :
Water, ammonia and sulfur

What best characterizes Jupiter's Great Red Spot?

A long-lived storm system about twice the size of the Earth.

The bulk of Jupiter's total mass is made up of,

Liquid Hydrogen

Jupiter's strong magnetic field is,

Expected, Jupiter's conducting liquid interior and rapid rotation should produce strong magnetism.

Compared to Jupiter's cloud layers, Saturn's cloud layers are,

Less colorful and thicker

Saturn's excess internal energy is due to,

The condensation and infalling of helium

Saturn's interior differs from Jupiter's in that Saturn's,

Has more atmosphere and less mantle.

What best describes Saturn's ring particles?

Icy snowballs

What accounts for the complex structure of Saturn's rings?

Gravitational resonance with small moons.

What is a difference between the discovery of Uranus and Neptune?

One of discovered by a telescope survey, one was discovered by calculating its orbit.

The rotation of Uranus on its axis is most similar to what other planet?

The rotation of Uranus is different from all the other planets.

Why do the atmospheres of Uranus and Neptune show fewer cloud features that the atmospheres of Jupiter and Saturn?

Since Uranus and Neptune are cooler, clouds form lower in the atmosphere where we can't see them.

How do the magnetic fields of Uranus and Neptune differ from the magnetic fields of Jupiter and Saturn?

The magnetic fields of Uranus and Neptune are displaced from the centers of the planets.

What is the middle layer of Jupiter and Saturn's interior?
: What is the middle layer of Uranus and Neptune's interior?

Liquid metallic hydrogen :
Water/ammonia slush.

How does the interior of Callisto differ from the interiors of the other Galilean moons?

It is not differentiated.

What is the origin of the Galilean moons?

They formed in place from a nebula surrounding Jupiter.

Why is Io so volcanically active?

Jupiter's tidal force squeezes and flexes Io, generating heat via friction.

Why do we think that Europa may have liquid water oceans under its surface?

a. We see ice rafts that seem to have broken up and then re-frozen in place.
b. We see smooth areas where craters have been erased by up-welling water.
c. Galileo detected a variable magnetic field on Europa.

What best describes the surface of Ganymede

Older dark terrain and newer light water ocean

What is the principal component of Titan's atmosphere?
: What is the most common type of precipitation on Titan?

: Methane.

what chemicals cause the opacity of titan's atmosphere

ethane and propane

what is true about the lakes of titan

they change size and shape over time

what is unusual about the orbit of triton

it has an inclined, retrograde orbit

which outer planet moon has geysers of nitrogen erupting form the south pole


Which of the following is true about the orbit of Pluto?

a. it is highly inclined.
b. It has a large eccentricity.
c. It is in a "safe" resonance with Neptune.

What property of Pluto did the discovery of its moon Charon allow us to learn?

Mass and radius.

Which of the following compounds is an important constitute of Kuiper Belt objects?


at what distance form the sun is the kuiper belt

30-50 AU

what is the estimated number of trans-neptunian objects larger than 100 km


the first transneptunian object was discovered in _______ : The second trans-neptunian object was discovered in _______.


What trans-neptunian object discovered in 2002 is roughly 1200 km across?


Why isn't Pluto considered a planet (by the IAU)?

There are many other similar objects near it in similar orbits.

Which is the following is the largest object in the trans-Neptunian region?


our best information about Pluto comes from _________, which visited Pluto in _________.

New Horizons: 2015

Most of a comet's mass is in the _______ : Most of a comet's light comes from the _________ .

Nucleus :

What is true about the directions in which the dust and ion tails point?

They are always pointed away from the Sun, but the dust tail is curved a little due to gravity.

How do the orbits of comets differ from the orbits of planets?

a. Comet orbits are more eccentric.
c. Comet orbits are more inclined.

Which phrase best describes the composition of a comet nucleus?

Dirty snowball

What can cause a comet's orbit to deviate from a Keplerian ellipse?

Outgasing jets of material from the comet.

Which best describe the layers of the Sun from the inside out in terms of energy generation and transport?

Fusion, radiation, convection, magnetic fields.

What do we see when we look at the photosphere carefully in visible light?

a. Granules
b. sunspots
c. Absorption lines

Which of the following particles is not part of the proton-proton chain?


During sunspot maximum we would expect,

The number of coronal mass ejections to be at a maximum.

Which of the following would be seen in a spectrum of the corona, but not in a spectrum of the photosphere?

Highly ionized iron

How does the radial velocity method detect planets around other stars?

By measuring periodic variations in the star's spectral lines.

How does the transit method detect planets around other stars?

By measuring the light the planet blocks out from the star.

How are exoplanets imaged directly?

By using a coronagraph to block the light from the star.

In what case can the radial velocity method not be used to find a planet?

If the motion is perpendicular to our line of sight.

What space mission has detected the most exoplanets? : What method did it use?

Kepler : Transit

What types of exoplanets were easiest to find by early detection methods?

Planets about the size of Jupiter, but in close orbits.

What is our best theory for producing a gas giant planet in a close orbit?

The gas giant formed in the outer system and then migrated inward due to friction with the disk.

What defines a Super-Earth?

Mass between 2-10 Earth masses.

What is needed to find the density of an exoplanet?

Both the mass and the radius.

Objects too large to be a planet, but too small to be a star are called,

brown dwarfs