Chapter 4 The Solar System AST 220

Meteorites are important because A) large ones may cause mass extinctions. B) they contain pristine material from the solar nebula. C) some come from the Moon and Mars, as well as the asteroid belt. D) All of the above are true. E) None of the above are true.

All of the above are true.

Meteor showers are A) usually annual events, as the orbits again intersect. B) caused by the Earth passing near the orbit of an Earthgrazing asteroid. C) caused by the Earth passing near the orbit of an old short-period comet. D) Both A and B are correct. E) Both A and C are correct.

Both A and B are correct.

The largest asteroid, and probably the only one to be a spherical "world" is A) Gaspra. B) Ceres. C) Ida. D) Vesta. E) Eros.

Ceres.

Which planet by itself contains the majority of mass of all the planets? A) Venus B) Jupiter C) Saturn D) the Earth E) Uranus

Jupiter

Which of the following are the jovian planets? A) only Jupiter and Saturn B) only Jupiter C) Jupiter, Saturn, Uranus, Neptune, and Pluto D) everything past Mars and the asteroid belt E) Jupiter, Saturn, Uranus, and Neptune only

Jupiter, Saturn, Uranus, and Neptune only

The first spacecraft to land on the surface of an asteroid was named A) Galileo. B) Dawn. C) NEAR. D) Giotto.

NEAR.

What is true about solar system densities? A) Planetary density increases with increasing distance from the Sun. B) The denser planets lie closer to the Sun. C) The asteroids all have about the same density. D) In differentiated bodies, the denser materials lie near their surfaces. E) Saturn has the same density as water.

The denser planets lie closer to the Sun.

Which statement about asteroids is not true? A) Their images become blurry due to outgassing as the Sun heats them up. B) Most stay between the orbits of Mars and Jupiter. C) They vary considerably in composition, reflectivity, and size. D) Earthgrazers can cross not only our orbit, but even those of Venus and Mercury. E) Some have satellites of their own.

Their images become blurry due to outgassing as the Sun heats them up.

A meteorite is A) a streak of light in the atmosphere. B) an icy body with a long tail extending from it. C) a chunk of space debris that has struck the ground. D) an irregularly shaped body, mostly found orbiting between Mars and Jupiter. E) a chunk of space debris orbiting the Earth.

a chunk of space debris that has struck the ground.

The nucleus of a comet is typically A) very durable, made of iron. B) a few meters in diameter. C) a few kilometers in size, and very low in density. D) located between the orbits of Mars and Jupiter. E) a few hundred kilometers across, and bright, shiny white from its ices.

a few kilometers in size, and very low in density.

The Manicouagan reservoir near Quebec is an example of A) cometary debris. B) a volcanic event. C) Earth's interaction with a comet's dust tail. D) a micrometeorite impact. E) a large meteorite impact.

a large meteorite impact.

The Oort Cloud is believed to be A) the circular disk of gas around the Sun's equator from which the planets formed. B) the great nebula found just below the belt stars of Orion. C) a grouping of asteroids and meteoroids between the orbits of Mars and Jupiter. D) a spherical cloud of cometary nuclei far beyond the Kuiper Belt. E) a flattened belt of cometary nuclei just beyond the orbit of Neptune.

a spherical cloud of cometary nuclei far beyond the Kuiper Belt.

A meteor is A) a streak of light in the atmosphere. B) an irregularly shaped body, mostly found orbiting between Mars and Jupiter. C) an icy body with a long tail extending from it. D) a chunk of space debris orbiting the Earth. E) a chunk of space debris that has struck the ground.

a streak of light in the atmosphere.

The jovian planets A) all spin slower than the Earth. B) all lie less than 5 AU from the Sun. C) have satellite systems with less than 4 moons. D) are all much more dense than any of the terrestrial planets. E) all have rings around their equators.

all have rings around their equators.

Planetary orbits A) have the Sun at their exact center. B) are highly inclined to the ecliptic. C) are evenly spaced throughout the solar system. D) are almost circular, with low eccentricities. E) are spaced more closely together as they get further from the Sun.

are almost circular, with low eccentricities.

Which of the following is not icy in composition? A) most jovian satellites B) comet nuclei C) asteroids D) Kuiper Belt Objects E) the polar cap of Mars

asteroids

The tail of a comet always points A) in the direction of the comet's motion. B) toward Earth and never varies. C) toward the Sun and disappears at perihelion. D) away from the Sun and becomes longest and brightest at perihelion. E) away from the Sun and disappears at perihelion.

away from the Sun and becomes longest and brightest at perihelion.

The Kuiper Belt is found where in the solar system? A) between the orbits of Jupiter and Uranus B) beyond the orbit of Neptune C) among the orbits of the terrestrial planets D) between the orbits of Mars and Jupiter E) sixty degrees ahead or behind Jupiter

beyond the orbit of Neptune

If a comet's ion tail is pointing perpendicular to its direction of travel, the comet is A) close to or at aphelion. B) moving closer to the Sun. C) A comet's tail never points perpendicular to its motion. D) close to or at perihelion. E) moving away from the Sun.

close to or at perihelion.

Which of these bodies are most likely to break up over time? A) Trojan asteroids B) jovian satellites C) asteroids in the main belt D) comet nuclei E) Kuiper Belt bodies

comet nuclei

Which of the following have an icy composition? A) comets B) most asteroids C) meteorites and most asteroids D) the surface of Mars E) meteoroids

comets

The most distant objects in our solar system are A) in the Kuiper Belt. B) the Trojan asteroids. C) the jovians. D) in the Oort Cloud. E) short period comets.

in the Oort Cloud.

So far, beyond the solar system the extrasolar planets found have been mostly A) large jovians orbiting solar-type stars about where our jovians are found. B) terrestrials with very elongated, distant orbits like comets. C) large jovians very close to their star. D) brown dwarfs much more massive than Jupiter. E) terrestrials very close to their star, and transiting its disk.

large jovians very close to their star.

The orbits of most comets A) are like the planets, fairly circular and in the ecliptic plane. B) lie almost entirely beyond the orbit of Neptune. C) are shorter than the 76-year period for Comet Halley. D) go no farther out than Pluto, then return to the sun again. E) have perihelions within the orbits of Mercury.

lie almost entirely beyond the orbit of Neptune.

Objects in the Kuiper belt A) are the sources of long-period comets. B) are dense, like the iron meteorites. C) lie beyond the orbit of Neptune, and close to the ecliptic. D) lie beyond the orbit of Neptune and perpendicular to the ecliptic. E) are in random orbits at all inclinations to the ecliptic.

lie beyond the orbit of Neptune, and close to the ecliptic.

Density is defined as A) weight divided by the planet's radius. B) mass per unit volume. C) mass times weight. D) size divided by weight. E) weight per square inch.

mass per unit volume.

Planetary transits of exoplanets are rare because A) the Earth's atmosphere interferes with our observations of transits. B) most extrasolar systems are not seen edge-on. C) most stars are too bright for us to detect a planetary transit. D) most exoplanets are smaller than Pluto. E) our telescopes are not powerful enough to detect them.

most extrasolar systems are not seen edge-on.

Most of the extrasolar planets found so far were detected by A) detecting the oxygen in their atmospheres spectroscopically. B) noting the drop in the star's light as the planet transits its disk. C) imaging them with the HST in the infrared, where they are easier to stop. D) noting the Doppler shifts of the star as the planet orbits it from side to side. E) receiving radio transmissions from them, much like Jupiter emits.

noting the Doppler shifts of the star as the planet orbits it from side to side.

Which of the following does not fall into the category of interplanetary debris? A) comets B) meteoroids C) Kuiper Belt bodies D) rings around the jovian planets. E) Trojan asteroids

rings around the jovian planets.

According to the Solar Nebula theory, planets A) will revolve opposite the star's rotation. B) should be a common result of star formation. C) should orbit perpendicular to their star's equator. D) should be extremely rare. E) should be randomly oriented to their star's equator.

should be a common result of star formation.

The Trojan asteroids are found A) orbiting around the Kuiper Belt body Hector. B) closer on average to the Sun than is the Earth. C) sixty degrees ahead or behind Jupiter, sharing its orbit about the Sun. D) beyond Neptune, with orbits similar to Pluto's. E) with the others, between Mars and Jupiter; their red color gives them their name

sixty degrees ahead or behind Jupiter, sharing its orbit about the Sun.

As a rotating gas cloud contracts, it spins A) slower due to conservation of angular momentum. B) faster due to an increase in angular momentum. C) at a constant rate. D) faster due to conservation of angular momentum. E) slower due to a decrease in angular momentum.

slower due to conservation of angular momentum.

The most detailed look we've had of an asteroid comes from A) ground based optical images. B) ground based radar images. C) Earth orbital X-ray images. D) spacecraft sent to an asteroid. E) high-altitude UV spectroscopy.

spacecraft sent to an asteroid.

As the solar nebula contracts, it A) spins faster due to conservation of angular momentum. B) cools due to condensation. C) loses angular momentum. D) flattens out into the ecliptic plane around the Sun's poles. E) reverses its direction of rotation.

spins faster due to conservation of angular momentum.

Long-period comets are believed to originally come from A) the Kuiper belt. B) the interstellar medium. C) the Oort cloud. D) the asteroid belt. E) the satellite system of Jupiter.

the Oort cloud.

Before it arrived in orbit about Jupiter, the Galileo spacecraft flew past A) Saturn. B) Comet Halley. C) the asteroid Ceres. D) Mars. E) the asteroid Gaspra.

the asteroid Gaspra.

Before it arrived in orbit about Eros, the NEAR spacecraft visited A) Mars. B) the asteroid Mathilde. C) the Moon. D) the asteroid Gaspra. E) Venus.

the asteroid Mathilde.

Iron meteorites are believed to come from A) the crust of a differentiated asteroid, now broken up. B) interstellar space. C) debris from the Kuiper Belt. D) the core of a differentiated asteroid, now broken up. E) a broken up cometary nucleus.

the crust of a differentiated asteroid, now broken up.

Relative to the comet, the direction of the ion tail tells us A) the direction the comet is traveling. B) the velocity of the comet. C) the direction of the Sun. D) where the ecliptic is. E) where the comet came from.

the direction of the Sun.

In terms of composition A) the terrestrials are more like the Sun, since they formed close to it. B) the jovian planets are made only of ice, and the terrestrials only of rock. C) the Sun is unique, made of nothing but hydrogen and helium. D) the jovian planets are more like the Sun than are the terrestrials. E) all planets condensed from the same nebula, and have similar compositions.

the jovian planets are more like the Sun than are the terrestrials.

The larger terrestrial planets have surface features that tend to be A) more rocky. B) more cratered. C) more icy. D) younger. E) older.

younger.