Astro Chap 11 ....
The eccentricity of Jupiter's orbit is:
0.048
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 Jupiter's strong magnetic field is caused by
a huge layer of metallic hydrogen inside Jupiter
The Red Spot of Jupiter is:
a. variable in size b. a high pressure storm system in the atmosphere c. made of a reddish colored material (but we don't know what gives it the reddish color) d. long-lived (observed since the 1600's) Correct Response e. all of the above
Which of the following is NOT a correct statement about the ways the jovian planets differ from the terrestrial planets?
b. all the jovians have satellites around them and none of the terrestrials do
Which element plays the same role on Titan as water does on Earth (existing as gas, liquid, and solid)?
b. methane
What evidence can you give that shows the surface of Jupiter's moon Europa must be relatively young?
b. we see very few craters compared to the surfaces of Callisto and Ganymede
What features are abundant on Callisto and Ganymede and almost absent on Europa and Io?
c. impact craters
The lakes found in the north polar region of Titan are filled with liquid
c. methane
The mountains on Pluto are made of frozen water, which at Pluto temperatures, is as hard as rock. Pluto also has a smooth, round basin which could be thought of as a frozen sea. What material is in the basin (nicknamed Sputnik) likely to be made of?
c. nitrogen
Callisto, the fourth moon of Jupiter's, takes 17 days to orbit Jupiter. If I stand on the surface of Callisto and see Jupiter high in the sky over my head, and then wait 8.5 Earth days in the same spot, where will I see Jupiter?
c. overhead, where it was before
Our modern understanding of Pluto is that it is a member of
c. the Kuiper Belt (of trans-Neptunian objects)
What is the cause of its many volcanic/geyser-like eruptions on the moon Io?
c. the gravitational stress of being so close to Jupiter and its other large moons heats the Io's inside
Which of the following statements about the geysers on the moon Triton is true?
c. they involve plumes of nitrogen on the sunlit side of Triton
The Galileo spacecraft measured that the moon Ganymede had a magnetic field, indicating that its interior was at least partly melted and warm. What do scientists think is the most likely reason for this?
d. Ganymede is heated by tidal forces from Jupiter
The same astronomer wrote extensively about canals on Mars and about the possibility of a ninth planet in our solar system. The observatory named after this astronomer is the:
d. Lowell Observatory
When astronomers say that Ganymede is a differentiated body, they mean that it:
d. has a heavier core, surrounded by a lighter, icy mantle and crust
Which of the following statements about Charon is FALSE?
d. it has a significant atmosphere
If I stood on the surface of Pluto, observing its big moon, I would see that moon:
d. remain in the same place in the sky
The majority of the moons orbiting the outer (jovian) planets are:
d. small moons orbiting in a retrograde direction (opposite to the direction their planet turns and orbits)
What method was used to discover Pluto in 1929-1930?
d. take pairs of photographs several days apart and "blink" them
For a while, after the space age began, astronomers did not know what the surface of Titan looks like, but today they do. Which of the following was NOT
d. using the Hubble Space Telescope in orbit to take a photo of Titan
Which of the following is NOT one of the largest moons in the Solar System?
e. Atlas (the shepherd moon near Saturn's A ring)
The moon Triton orbits which of the planets?
e. Neptune
Which planet has the biggest moon relative to its own size? Not the biggest moon in terms of kilometers, but the biggest as a percentage of the size of the planet it orbits.
e. Pluto
Two worlds in the outer solar system that seem remarkably similar to each other are:
e. Pluto and Triton
Which of the following is NOT a way that the moon Titan probably resembles the Earth?
e. at its surface the temperature and pressure are just right for water to exist in all three phases (gas, liquid, and ice)
Which of the jovian planets does NOT have any satellites?
e. you can't fool me, all the jovian planets are accompanied by satellites
The big problem with the Galileo spacecraft is that
its main antenna is stuck in the closed position
What was a surprise to astronomers when they carefully examined Neptune with the Hubble Space Telescope in 1994?
the Great Dark Spot had disappeared
Approximately how long does it take for Jupiter to complete one orbital revolution around the Sun?
11 years and 10 months
What is the distance in kilometers from Saturn inside which a moon would be torn apart by tidal forces?
147,000 km
Jupiter has enough mass to make 318 Earths. In contrast, Uranus and Neptune have only enough mass to make
15 Earths
How far is the center of Pluto from the center of mass point for the Pluto-Charon system?
2,080 km
Approximately how long does it take Jupiter to complete one rotation?
10 hours
Approximately how long does it take for Jupiter to undergo one complete rotation?
10 hours
What is the perihelion distance of Eris?
38 AU
How far is Voyager from Earth at this point? Hint: Use the Measurement Tool.
4.5 AU
Mercury has a diameter of 4,800 km. Which of the Galilean moons of Jupiter is larger than Mercury?
Ganymede
The Galilean satellites, in order of decreasing diameter, are:
Ganymede, Callisto, Io, Europa
The first spacecraft to explore the environment of the planet Jupiter was called
Pioneer
The atmosphere on Jupiter rotates in a direction that is parallel to Jupiter's equator.
True
Pluto was discovered through the patient searching of
b. Clyde Tombaugh
The world in the solar system that is most active volcanically is:
c. Io
The primary clouds in the atmospheres of Jupiter and Saturn are composed of:
frozen ammonia crystals
The synchrotron radiation (radio waves) that astronomers first observed from Jupiter in the 1950's comes from:
high speed electrons spiraling around the planet's strong magnetic field
Which of the following does the composition of a planet like Jupiter resemble:
the Sun
The perihelion distance for Jupiter is:
4.951 AU
The length of the semi-major axis for Jupiter in its orbit is:
5.204 AU
The aphelion distance for Jupiter is:
5.457 AU
The atmosphere around Saturn's North Pole flows in a geometric pattern that posseses: (Note: You might find it advantageous to press the Stop time control to make your number count easier.)
6 sides (hexagon)
What are the advantages of a robotic craft over a manned mission?
A robotic spacecraft does not have to be returned to Earth.
Phobos and Deimos most closely resemble:
Asteroids
There is a distinctly shaped geometric pattern (a polygon shape) in gas flow over the South Pole, while the North Pole seems to exhibit a predominantly circular flow.
False
The first spacecraft which did not merely fly by a jovian (or giant) 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
How does this Cassini view differ from views provided by the Hubble Space telescope?
It shows the night side of Saturn.
Apart from low mass and large distance from the Sun, what other reason is there for Pluto's removal from the list of major planets?
Its orbit is highly inclined to the plane of the ecliptic.
Which factor or factors, more than any other, have allowed Titan to retain an atmosphere?
Its surface temperature is too low to allow the nitrogen gas in its atmosphere to escape from Titan's gravitational force.
New Horizons achieved its closest approach on:
July 14, 2015
Voyager 2 achieved its closest approach to Jupiter (and the Red Spot) on:
July 9, 1979
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 has 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 far 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 (period of revolution) is:
Neptune
Which of the following features of Pluto's orbit is NOT true?
Pluto's orbital speed is constant as it moves along its orbit.
How does the position of the center of mass compare with Pluto's radius of about 1200 km?
The center of mass is above the surface of Pluto.
What factor, more than any other, do you think led to Jupiter having so many moons compared to the inner terrestrial planets?
The powerful gravitational field produced by Jupiter's large mass has allowed this planet to capture moons from the nearby asteroid belt.
The eccentricity of the outer planets' orbits is close to zero.
True
The length of the year on Jupiter is equal to 11.86 Earth years.
True
The reason for the difference in aphelion and perihelion distances is because Jupiter's orbit is not circular, but is instead elliptical:
True
The sum of the aphelion and perihelion distances is equal to the diameter of Jupiter's elliptical orbit at its widest or greatest distance:
True
The planet that orbits "on its side" (i.e. has its rotation axis perpendicular to the plane of its orbit) is:
Uranus
At their centers, all the jovian planets have cores made of:
a solid mixture of rocky and icy materials under great pressure
Pluto's big satellite is called
a. Charon
The satellite whose surface is characterized by a smooth icy crust with a complex network of cracks is:
a. Europa
The largest satellite (moon) in the solar system is:
a. Ganymede
The dwarf planet Pluto was discovered in 1930. Since that time, which jovian planet has completed a full revolution around the Sun?
a. Jupiter b. Saturn c. Uranus d. Neptune Correct Response e. more than one of the above
What do astronomers think is the origin of the many irregular moons around the outer planets (irregular meaning they are orbiting backwards and/or have eccentric orbits)?
a. These moons were likely formed elsewhere and captured by the giant planets
The spacecraft that visited Pluto and send back our first images:
a. was called New Horizons b. got a gravity boost from Jupiter to get it to Pluto faster c. used plutonium to keep it warm d. is returning to Earth in the 22nd century Correct Response e. more than one of the above
After having looked at how the atmosphere in each of the four outer planets rotates, I conclude that:
all of the four gas giants have atmospheres that rotate parallel to the equator.
What do the magnetic fields of Jupiter, Uranus, and Neptune have in common?
all three have their magnetic axes offset from the center of the planet
The four large moons of Jupiter were first discovered by:
b. Galileo with his early telescope
The satellite which has the thickest atmosphere (so thick that it's quite a surprise for a satellite) is:
b. Titan
By far the most abundant element in the giant (jovian) 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
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 statements about the Galileo probe that dropped into Jupiter is FALSE?
it detected a lot of water and water vapor clouds on its way down
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
Which of the following is NOT a way that Jupiter differs from terrestrial planets?
its surface has many more craters from early collisions
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 what gas?
methane
The upper clouds in the atmosphere of Neptune are composed of:
methane
To obtain the wonderful images of the jovian planets in our textbook (out where the sunlight is a lot fainter) what did the Voyager spacecraft cameras have to do as they flew by each world?
swivel the cameras backwards to keep pointing in the same direction as the craft flew by
What allowed the Voyager 2 spacecraft to make a "tour" of all four of the jovian planets in the late 1970's and the 1980's?
the four planets were approximately aligned on one side 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
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 on 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
