ASTR Q9

The first spacecraft to explore the environment of the planet Jupiter was called 1) Viking 2) Mariner 3) Apollo 4) Voyager 5) Pioneer

5) Pioneer

The Red Spot of Jupiter is: 1) variable in size 2) a high pressure storm system in the atmosphere 3) made of a reddish colored material (but we don't know what gives it the reddish color) 4) long-lived (observed since the 1600's) 5) all of the above

5) all of the above

Which of the following is NOT a way that Jupiter differs from terrestrial planets? 1) its average density is lower 2) it is farther away from the Sun 3) it includes much more gas and liquid 4) it is larger in diameter 5) it has many more craters from early collisions

5) it has many more craters from early collisions

The planet Pluto was discovered in 1930. Since that time, which jovian planet has completed a full revolution around the Sun? 1) Jupiter 2) Saturn 3) Uranus 4) Neptune 5) more than one of the above

5) more than one of the above

By far the most abundant element in the giant (jovian) planets is: 1) helium 2) hydrogen 3) oxygen 4) nitrogen 5) silicon

2) hydrogen

The synchrotron radiation that astronomers first observed from Jupiter in the 1950's comes from: 1) deep inside the metallic hydrogen layers 2) high speed electrons spiraling around the planet's strong magnetic field 3) the upper atmosphere clouds that move so quickly near the equator of the planet 4) the Red Spot with its tremendous friction 5) you can't fool me, that radiation turned out to come from stars that happened to lie behind Jupiter during the 1950's

2) high speed electrons spiraling around the planet's strong magnetic field

As the Voyager spacecraft penetrated into the outer solar system, the illumination from the Sun declined. Relative to the situation at Earth, how bright is the sunlight at Jupiter? Jupiter's semi-major axis is 5.2 AU. Round your answer to two decimal places.

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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 1) Galileo 2) Einstein 3) Voyager 4) the Hubble Space Telescope 5) Cassini

1) Galileo

Which of the jovian planets has the shortest period of rotation (the shortest day)? 1) Jupiter 2) Saturn 3) Uranus 4) Neptune 5) you can't fool me, the length of the day is exactly the same on all the giant planets

1) Jupiter

The planet that orbits "on its side" (i.e. has its rotation axis perpendicular to the plane of its orbit) is: 1) Uranus 2) Neptune 3) Pluto 4) Jupiter 5) Saturn

1) Uranus

What do the magnetic fields of Jupiter, Uranus, and Neptune have in common? 1) all three have their magnetic axes offset from the center of the planet 2) all are weaker than the Earth's magnetic field 3) all are caused by molten iron and nickel deep within each planet 4) all are tilted by about 50 or 60 degrees from the planet's axis of rotation 5) all were discovered by spacecraft that flew by the planets

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

Large, gaseous planets like Jupiter can still generate significant amounts of heat today by: 1) shrinking slightly under their own gravity 2) expanding slightly with the heat of the Sun 3) the action of magnetic fields deep inside, which can capture hot particles from space 4) the friction produced as they wobble slightly in their orbits 5) increasing their speed of rotation

1) shrinking slightly under their own gravity

Which of the following is NOT a way the jovian planets differ from the terrestrial planets? 1) the jovians are larger 2) all the jovians have satellites around them and none of the terrestrials do 3) the jovians are made mostly of liquid and gas 4) the jovians are typically colder and further from the Sun 5) the jovians have rings while the terrestrials do not

2) all the jovians have satellites around them and none of the terrestrials do

What is one important source of particles to circulate around Jupiter's magnetic field? 1) comets that come into the Jupiter system 2) particles expelled from volcanoes on the moon Io 3) the extensive ring system around Jupiter 4) eruptions (like geysers) on the surface of Jupiter 5) the sources of these particles is a complete mystery

2) particles expelled from volcanoes on the moon Io

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? 1) NASA had developed a new kind of rocket that could propel the craft from planet to planet 2) 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 3) the spacecraft stopped off to collect fuel on the satellites of each planet before proceeding to the next one 4) we used laser beams to propel the spacecraft into the outer solar system, where sunlight is dim 5) you can't fool me, no single spacecraft has ever explored four different planets

2) 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

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?Which of the following characteristics distinguishes Uranus from every other planet in our solar system? it has more than one moon its atmosphere is made of gases it rotates on an axis tilted almost 90 degrees to the circle of its orbit its orbit is significantly tilted relative to the orbits of the other planets its magnetic axis does not lie in the same direction as its rotation axis 1) the south pole was in darkness 2) the south pole was brightly lit, with the Sun shining down on it 3) the south pole was in twilight 4) the south pole was facing directly away from the Sun 5) more than one of the above

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

Astronomers believe that the strong magnetic field on Jupiter is caused by 1) a core of molten iron and nickel 2) electric charges from the moon Io 3) a huge layer of metallic hydrogen inside Jupiter 4) the circulation of large reddish storms containing magnetic ammonia crystals 5) the magnetic personalities of all the jovian movie stars that live there

3) a huge layer of metallic hydrogen inside Jupiter

The primary clouds in the atmospheres of Jupiter and Saturn are composed of: 1) water vapor 2) iron and nickel 3) frozen ammonia crystals 4) metallic hydrogen 5) frozen alcohol crystals

3) frozen ammonia crystals

Which of the following characteristics distinguishes Uranus from every other planet in our solar system? 1) it has more than one moon 2) its atmosphere is made of gases 3) it rotates on an axis tilted almost 90 degrees to the circle of its orbit 4) its orbit is significantly tilted relative to the orbits of the other planets 5) its magnetic axis does not lie in the same direction as its rotation axis

3) it rotates on an axis tilted almost 90 degrees to the circle of its orbit

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? 1) use faster (more light sensitive) film 2) slow down the spacecraft using retro-rockets to get long exposures 3) swivel the cameras backwards to keep pointing in the same direction as the craft flew by 4) use more than one camera and combine the light that fell into each one 5) simply make do with pictures that got worse and worse as we went outward from the Sun; by the time we got to Neptune, the images were quite blurry

3) swivel the cameras backwards to keep pointing in 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? 1) the magnetic field of the planet had reversed (north was now south) 2) new elements and compounds were found in the upper atmosphere that had not been there before 3) the Great Dark Spot had disappeared 4) the wind speeds had slowed considerably 5) a large smiley-face had been constructed using dark clouds

3) the Great Dark Spot had disappeared

Which of the following statements about the seasons on Jupiter is correct? 1) Jupiter has seasons pretty much like the Earth; its axis has the same tilt, and each season is about the same length 2) Jupiter has the same axis tilt as the Earth, but each season on Jupiter is much longer 3) Jupiter's axis is tilted much more than the Earth's so its seasons are much more intense 4) Jupiter's axis is hardly tilted so it has no real seasonal variations 5) Jupiter's orbit brings it much closer to the Sun in summer and much farther from the Sun in winter

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

The jovian planet that has the longest year (period of revolution) is: 1) Jupiter 2) Saturn 3) Uranus 4) Neptune 5) you can't fool me, they all have roughly the same year

4) Neptune

At their centers, all the jovian planets have cores made of: 1) hydrogen and helium in the form of gas 2) hydrogen and helium in the form of liquids 3) methane, ammonia, and sulfur compounds 4) a solid mixture of rocky and icy materials under great pressure 5) new elements produced by the high pressure; elements which we do not have on Earth

4) a solid mixture of rocky and icy materials under great pressure

Which of the following statements about Jupiter's magnetosphere is TRUE? 1) its source is a zone directly above the planet's cloudtops 2) the magnetic field that causes it is 20 to 30 times weaker than the Earth's 3) it is tilted so that it is almost perpendicular (at 90 degrees) to the equator of Jupiter 4) it completely covers the inner satellites of Jupiter and is one of the largest structures in the solar system 5) it is easily visible to the human eye with a small telescope

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

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? 1) carbon dioxide 2) oxygen 3) argon 4) methane 5) helium

4) methane