Week 5 Astronomy

On both Jupiter and Saturn, the water clouds are thought to form at pressures of

10 bars

Jupiter has enough mass to make 318 Earths. In contrast, Uranus and Neptune have only enough to make

15 Earths

Triton and Pluto are very cold worlds in the outer reaches of the solar system. They are similar in size (between ____ and ___ km) and similar in density, and thus similar in the proportion of rock and ice that makes them up. Both have a atmosphere of _______, which freezes and sublimates depending on the temperature. Both have irregular or unusual orbits, with Triton moving in retrograde orbit and Pluto in a tilted ____ elliptical orbit. Astronomers think that Triton may be a captured moon from the realm of trans-Neptunian dwarf planets like Pluto.

2000, 3000, thin, nitrogen, highly

On both Jupiter and Saturn, the water clouds are thought to form at temperatures of about

300 K

The first spacecraft which did not merely fly by a jovian planet, but actually went into orbit around it for an extended period of time was

Galileo

Which of the following spacecraft is NOT leaving the solar system

Galileo

Which of the following characteristics distinguishes Uranus from every other planet in our solar system?

It rotates on an axis tilted almost 90 degrees to the circle of its orbit

The largest planet in the solar system by mass is

Jupiter

The planet that has an axis that points roughly straight up, and thus has no seasons to speak of is

Jupiter

Which of the jovian planets had the shortest period of rotation (the shortest day)?

Jupiter

Which of the following statements about the seasons on Jupiter is correct?

Jupiter's axis is hardly tilted so it has no real seasonal variations

In the future, a daring interplanetary tourist wants to go "hang-gliding" on the jovian planet with the highest equatorial wind speeds. Which planet would have the fastest wind at its equator?

Neptune

The jovian planet that has the longest year is

Neptune

What are the visible clouds on the four giant planets composed of

On Uranus and Neptune the clouds are composed of methane The clouds of Jupiter and Saturn are primarily crystals of frozen ammonia

The first spacecraft to explore the environment of the planet Jupiter was called

Pioneer

What are the seasons like on Jupiter?

Since Jupiter's spin axis is only tilted about 3 degrees from the perpendicular, it does not experience seasons at all.

Why do the upper levels of Neptune's atmosphere appear blue?

The gaseous molecules in Neptune's atmosphere scatter blue light, giving Neptune its color

What is the source of Jupiter's strong magnetic field

The large, rapidly spinning, liquid-metallic hydrogen above the core

The planet that orbits on its side is

Uranus

Much of what we have learned about the jovian planets and their satellites has come from the work of two spacecraft called

Voyager

Astronomers believe that Jupiters strong magnetic field is caused by

a huge layer of metallic hydrogen inside Jupiter

At their centers, all the jovian planets have cores made of

a solid mixture of rocky and icy materials under great pressure

The Red Spot of Jupiter is

all of the above

Which of the following is NOT a correct statement about the ways the jovian planets differ from the terrestrial planets?

all the jovians have satellites around them and none of the terrestials do

What do the magnetic fields of Jupiter and Neptune have in common

all three have their magnetic axes offset from the center of the planet

The rings of Uranus are thin and hard to see, consisting mostly of chunks of __________ and ___________ with very little reflectivity. They may also have formed from the breakup of a small moon due to a collision. They may be kept by the presence of ________.

carbon, hydrocarbon, shepherd moons

Uranus has no or very little internal heat so it gets its energy from the Sun (t/f)

false

The primary clouds in the atmospheres of Jupiter and Saturn composed of

frozen ammonia crystals

The sychroton radiation that astronomers first observed from Jupiter in the 1950s comes from

high speed electrons spiraling around the planet's strong metallic field

By far the most abundant element in the giant planets is

hydrogen

The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturn's magnetism is

hydrogen

The surface of Europa features jagged blocks of _________ that seem to have rotated and collided with one another, which would not likely happen on a solid moon. Long, straight ________ in the crust are also more likely to happen over a liquid subsuface layer than a solid one. Also, a weak __________ field implies the presence of a liquid layer below the surface. This is interesting for searchers of extraterrestrial life because ______________ its existence for life as we know it.

ice, cracks, magnetic, liquid water

Saturn's rings form a wide and complex system consisting mostly of particles and pieces of ________, and are highly visible. They may have formed one or more ________ that broke up due to ___________ or are left over from early debris that never coalesced into a moon.

ice, moon a collision

Which of the following statements about Jupiter's magnetosphere is TRUE?

it completely covers the inner satellites of Jupiter and is one of the largest structures in the solar system

Which of the following about the Galileo probe that dropped into Jupiter is FALSE?

it detected a lot of water and water vapor clouds on its way down

The big problem with the Galileo spacecraft is that

its main antenna is stuck in the closed position

Which of the following is NOT a way that Jupiter differs from terrestrial planets?

its surface has many more caters from early collisions

At the pressure in Jupiter's interior, describe the physical state of the hydrogen found there

liquid metallic form

One way to measure how long Jupiter takes to rotate is to watch the giant storms in its atmosphere go around. A more fundamental way to measure the rotation is to

measure the changes in the planet's radio waves which are controlled by its magnetic field

The bluish color that makes the atmosphere of Neptune so beautiful to the human eye is caused by the interaction of sunlight with which gas?

methane

The upper clouds in the atmosphere of Neptune are composed of

methane

The dwarf planet Pluto was discovered in 1930. Since that time, which jovian planet has completed a full revolution around the Sun?

more than one of the above

What is the primary source of Jupiter's internal heat?

primordial heat, left over from the formation of the planet 4.5 billion years ago

The moons of the outer planets consist of a mixture of _______, whereas our Moon is just _________

rock and ice, rock

Io volcanoes are fundamentally like those of Earth, erupting high-temperature ________ magma. However, the heat to power the volcanoes on Io comes from __________ whereas terrestrial volcanoes, derive their power from ___________ heating of the mantle. Volcanoes plumes are much _______ on Io than on Earth, due mainly to Io's lack of any atmosphere and to a Io a lesser extent, the lower ________ of Io.

silicate, tidal energy, radioactive, higher, surface gravity

To obtain the wonderful images of the jovian planets in our textbook what did the Voyager spacecraft cameras have to do as they flew by each world

swivel the cameras backwards to keep pointing the same direction as the craft flew by

What was a surprise to astronomers when they carefully examined Neptune with the Hubble Space Telescope in 1994?

the Great Dark Spot had disappeared

Which of the following does the composition of a planet like Jupiter resemble

the Sun

What allowed the Voyager 2 spacecraft to make a "tour" of all four of the jovian planets in the late 1970s and the 1980s

the four planets were approximately aligned on oneside of the Sun and we used the gravity of each planet to speed up the spacecraft to get to the next one in its path

One reason that we have such a complex system of belts/zones/storms in Jupiter's atmosphere is that

the planet rotates very rapidly

The same process that explains why astronomers see less helium in the upper atmosphere of Saturn when they take spectra also explains

the reason Saturn is warmer than we expect

Describe the interior heat source of Saturn

the sinking of heavier elements releases gravitational energy which heats the interior.

At the moment when the Voyager spacecraft got closest to Uranus, the Sun was shining directly on the planet's south pole. Uranus takes about 17 hours to rotate once over its axis. If Voyager took a photo of the south pole 8.5 hours later, what would it observe?

the south pole was brightly lit, with the Sun shining down on it

Io is close enough to Jupiter to experience significant ____________ where the moon alternately stretches and relaxes in its elliptical orbit about the planet. The generates enough __________ to produce molten silicate lava that erupts as _________.

tidal heating, heat, volcanoes

For Jupiter, Saturn, and Neptune, both the sunlight and internal sources provide energy to its atmosphere (t/f)

true