Astronomy 109 Ch. 14

Which of the following characterizes the Kuiper belt? A. It is a disk-like region between the outer planets and the Oort cloud. B. It is up to 100,000 AU in size and spherical in shape. C. It lies between the orbits of Mars and Jupiter. D. It is a stable region just ahead of Jupiter in its orbit. E. It is the region occupied by the Earth-crossing Apollo asteroids.

A. It is a disk-like region between the outer planets and the Oort cloud.

What is the defining property of the Trojan asteroids? A. They have orbits at the distance of Jupiter and 60 degrees ahead of or behind it. B. Like Pluto, they are in a 3:2 resonance with Neptune. C. Their orbital periods are exactly one year, like ours. D. They have orbits between Saturn and Uranus. E. They have orbits that cross the orbit of the Earth, but not that of Venus.

A. They have orbits at the distance of Jupiter and 60 degrees ahead of or behind it.

Trojan asteroids orbiting at Jupiter's Lagrangian points are located A. behind and in front of Jupiter, sharing its orbit. B. close to Jupiter. C. far outside Jupiter's orbit. D. between Mars and Jupiter.

A. behind and in front of Jupiter, sharing its orbit.

Spectroscopic studies indicate that the majority of asteroids contain large fractions of A. carbon. B. silicate rocks. C. ice. E. iron and nickel.

A. carbon.

The orbits of most asteroids: A. lie entirely beyond the orbit of Mars. B. cross the orbit of Mars. C. cross the orbit of Earth. D. cross the orbits of all four terrestrial planets. E. lie beyond Neptune.

A. lie entirely beyond the orbit of Mars.

Carbonaceous meteorites are believed to come from: A. the crust of a differentiated C type asteroid, now broken up. B. a broken up cometary nucleus, dark like Comet Halley's nucleus. C. deep space, far beyond the solar system, hence their very low density. D. the core of a differentiated type M asteroid, now broken up. E. coal formed on Mars, then blown into space by asteroid impacts.

A. the crust of a differentiated C type asteroid, now broken up.

Based on observations by the Dawn spacecraft, scientists have concluded that Vesta might be: A. the only remaining protoplanet in our solar system. B. a planetesimal leftover from the solar system's formation. C. a fragment of Mars. D. one of the remnants of the planet that broke up to form the asteroid belt. E. one of the dwarf planets in our solar system.

A. the only remaining protoplanet in our solar system.

Kuiper belt objects are not regarded as planets because A. their masses are too low to clear other bodies from their orbital paths. B. they orbit too far from the Sun. C. they are all irregular in shape without exception. D. they are predominantly icy in composition.

A. their masses are too low to clear other bodies from their orbital paths.

About what percent of all asteroids are S-type asteroids? A. 10% B. 15% C. 75% D. 5% E. 50%

B. 15%

When a formal definition of a planet in the solar system was adopted, Pluto was reclassified as a dwarf planet. What characteristic of planets does NOT describe Pluto? A. Planets orbit in ellipses with low eccentricity. B. Planets have cleared the neighborhood around their orbit. C. Planets orbit the Sun. D. Planets are approximately spherical. E. Planets orbit in or very near the ecliptic plane.

B. Planets have cleared the neighborhood around their orbit.

Large meteoroids are thought to collide with Earth: A. about once a century. B. a few times in every million-year period. C. at least once a decade. D. never; only comets are thought to collide with Earth. E. once every billion years.

B. a few times in every million-year period.

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

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

Compared with the orbits of the short-period comets, the orbits of long-period comets A. look like short-period orbits, but are simply much larger. B. can come from all directions. C. are much less eccentric. D. tend to lie in the plane of the ecliptic.

B. can come from all directions.

The Apollo and Aten asteroids have orbits that: A. cross the orbit of Mars, but not the Earth, at perihelion. B. cross the orbit of Earth at perihelion. C. remain between Mars and Jupiter, in the main belt. D. stay sixty degrees ahead of or behind Jupiter. E. stay out beyond Neptune.

B. cross the orbit of Earth at perihelion.

The Amor asteroids have orbits that: A. stay out beyond Neptune. B. cross the orbit of Mars, but not Earth, at perihelion. C. stay closer to the Sun, on average, than we do. D. stay sixty degrees ahead of or behind Jupiter. E. cross the orbit of Earth at perihelion.

B. cross the orbit of Mars, but not Earth, at perihelion.

The tail of a comet can consist of ________. A. rocky pebbles B. dust and gas C. rocky boulders D. ice chunks E. blonde hair

B. dust and gas

The Kuiper Belt objects have orbits that: A. stay sixty degrees ahead of or behind Jupiter. B. stay out just beyond Neptune and close to the ecliptic. C. carry them thousands of A.U. beyond the Sun. D. cross the orbit of Mars at perihelion. E. cross the orbit of Earth at perihelion.

B. stay out just beyond Neptune and close to the ecliptic.

Meteor shower debris is believed to come from: A. the asteroid belt when Mars deflects it toward us annually. B. the disintegration of a short period comet over many returns to the Sun. C. deep space, far beyond the solar system, deflected by the gravity of another star. D. the core of a differentiated type M asteroid, now broken up. E. the crust of a differentiated type C asteroid, now broken up.

B. the disintegration of a short period comet over many returns to the Sun.

The type of asteroid that would appear darkest and reflect the least light is type: A) A. B) B. C) C. D) D. E) S.

C) C.

What is the source of the material of a meteor shower? A. Solar wind B. Oort cloud C. Comets D. Collisions among asteroids

C. Comets

Which of the following is NOT one of the criteria necessary to classify an object as a major planet? A. It must have enough self-gravity to be approximately spherical. B. It has cleared its neighborhood around its orbit of other bodies. C. It must have at least one moon orbiting around it. D. It must orbit the Sun.

C. It must have at least one moon orbiting around it.

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

C. lie almost entirely beyond the orbit of Neptune.

The tails of a comet A. curve from right to left. B. point opposite the direction of motion of the comet. C. point away from the Sun. D. curve clockwise with the interplanetary magnetic field.

C. point away from the Sun.

The Trojan asteroids have orbits that: A. cross the orbit of Earth at perihelion. B. stay out beyond Neptune. C. stay sixty degrees ahead of or behind Jupiter. D. cross the orbit of Mars, but not Earth, at perihelion. E. are, on average, closer to the Sun than we are.

C. stay sixty degrees ahead of or behind Jupiter.

Iron meteorites are believed to come from: A. the crust of a differentiated type C asteroid, now broken up. B. a broken up cometary nucleus, hence their shiny appearance. C. the core of a dense M-type asteroid, now broken up. D. deep space, far beyond the solar system, hence their unique crystal patterns. E. Mars, hence their reddish color.

C. the core of a dense M-type asteroid, now broken up.

The Oort Cloud is thought to be: A. a cloud of debris that occasionally encounters the Earth, causing a meteor shower. B. a cloud of asteroids moving between the orbits of Mars and Jupiter. C. the spherical cloud of comets and some larger icy bodies surrounding the outer solar system. D. the cloud of gas and dust from which our solar system formed. E. the material in the ecliptic plane that creates the zodiacal light.

C. the spherical cloud of comets and some larger icy bodies surrounding the outer solar system.

About how many potentially hazardous asteroids pass within 0.05 AU of the Earth per decade in modern times? A. None B. 5000-1000 C. 10-20 D. 200-300 E. A completely unknown quantity; it could easily be anywhere from just a few to millions.

D. 200-300

The asteroids that cross the orbit of Earth belong to a group called the ________. A. Juno asteroids B. Kuiper asteroids C. Trojan asteroids D. Apollo asteroids E. Amor asteroids

D. Apollo asteroids

Pluto's density is most similar to: A. Saturn, but not Jupiter, Uranus, or Neptune. B. the jovian planets. C. the terrestrial planets. D. moons of the jovian planets. E. Mercury, but nor Venus, Earth, or Mars.

D. moons of the jovian planets.

The most common type of meteorite to strike Earth is ________. A. iron B. rocky iron C. carbonaceous D. rocky

D. rocky

A meteorite is a piece of interplanetary debris that A. burns up in Earth's atmosphere. B. misses Earth's surface. C. glances off Earth's atmosphere. D. survives the trip to the surface.

D. survives the trip to the surface.

Meteorites are valuable to astronomers because: A. they contain diamonds and gold. B. they originated in other solar systems. C. they prove that life can only exist on the Earth. D. they may provide evidence about the process in which the solar system was born. E. they reveal the contents of interstellar space.

D. they may provide evidence about the process in which the solar system was born.

About what percent of all asteroids are C-type asteroids? A. 10% B. 15% C. 5% D. 50% E. 75%

E. 75%

Which of the following objects never collide with the Earth? A. Aten asteroids B. short period comets C. long period comets D. Apollo asteroids E. Amor asteroids

E. Amor asteroids

The three largest asteroids are: A. Deimos, Phobos, and Athos. B. Halley, Hale-Bopp, and Hyakutake. C. Pluto, Sedna, and Quaoar. D. Ida, Gaspra, and Mathilde. E. Ceres, Pallas, and Vesta.

E. Ceres, Pallas, and Vesta.

From its orbit, we now recognize Pluto as one of the largest members of the: A. asteroid belt. B. moons of Neptune. C. Zodiacal Belt. D. Oort Cloud. E. Kuiper Belt.

E. Kuiper Belt.

The type of asteroid that would be the densest would be type: A. Z. B. V. C. C. D. S. E. M.

E. M

Most of the asteroids orbit the Sun in a belt between the orbits of ________. A. Earth and Mercury B. Mars and Earth C. Venus and Mars D. Jupiter and Saturn E. Mars and Jupiter

E. Mars and Jupiter

Long period comets are thought to reside mainly in the: A. Kirkwood gaps. B. Interstellar Medium. C. asteroid belt. D. Kuiper Belt. E. Oort Cloud.

E. Oort Cloud.

Which of the following gives direct information about the age of the solar system? A. Martian meteorites B. the oldest lunar basalts C. the solar wind D. the oldest Martian basalts E. meteorites from asteroidal debris

E. meteorites from asteroidal debris