Ch. 11: Asteroids, Meteors, Comets

What is Chicxulub? A) A Mexican town in the Yucatan near which a major impact may have occurred 65 million years ago. B) Chicxulub is the site of the failed launch of a Soviet space mission to the asteroid belt. C) This is the name of a comet that may have crashed into Earth exterminating the dinosaurs. D) Chicxulub is a type of large asteroid.

A) A Mexican town in the Yucatan near which a major impact may have occurred 65 million years ago.

What is a meteor? A) A glowing trail of hot gas and debris heated by friction as an object moves through the atmosphere. B) A space rock that survives its fall through the Earth's atmosphere and reaches the ground. C) The object that causes a "shooting star," but before it passes through the atmosphere. D) Any one of the large, rocky bodies that orbit the Sun, primarily between Jupiter and Saturn.

A) A glowing trail of hot gas and debris heated by friction as an object moves through the atmosphere.

What is a meteorite? A) A glowing trail of hot gas and debris heated by friction as an object moves through the atmosphere. B) A space rock that survives its fall through the Earth's atmosphere and reaches the ground. C) This is the object that causes a "shooting star," but before it passes through the atmosphere. D) Any one of the large, rocky bodies that orbit the Sun, primarily between Jupiter and Saturn.

B) A space rock that survives its fall through the Earth's atmosphere and reaches the ground.

Typical asteroids are irregularly shaped. Why is Ceres not so shaped? A) Ceres is near Earth; it was shaped into a sphere by Earth's gravitational force. B) Ceres is relatively massive; its gravitational force is strong enough to crush its material into a sphere. C) Ceres is near the Sun; the Sun's heat melted Ceres, and it solidified into a sphere. D) Ceres is shaped like all the other asteroids.

B) Ceres is relatively massive; its gravitational force is strong enough to crush its material into a sphere.

Why are there two tails to some comets? A) The "gas tail" is formed by solar radiation pressure. The "dust tail," is pushed out by the solar wind B) The "dust tail" is formed by solar radiation pressure. The "gas tail," is pushed out by the solar wind. C) Comets contain iron, which is attracted by the Sun's gravity, forming a tail which points toward the Sun. D) The statement is false: comets have only one tail.

B) The "dust tail" is formed by solar radiation pressure. The "gas tail," is pushed out by the solar wind.

Annual meteor showers such as the Perseids in August are caused by A) the breakup of asteroids that hit our atmosphere at predictable times. B) the Earth passing through the debris left behind by a comet as we cross its orbit. C) nuclear reactions in the upper atmosphere triggered by meteoritic particle storms. D) passing asteroids triggering auroral displays.

B) the Earth passing through the debris left behind by a comet as we cross its orbit.

Meteor showers such as the Perseids in August are caused by A)... the breakup of asteroids that hit our atmosphere at predictable times. B)... the Earth passing through the debris left behind by a comet as it moves through the inner Solar System. C)... passing asteroids triggering auroral displays. D)... nuclear reactions in the upper atmosphere triggered by an abnormally large meteoritic particle entering the upper atmosphere. E)... None of the above.

B)... the Earth passing through the debris left behind by a comet as it moves through the inner Solar System.

What is the Kuiper Belt? A) A swarm of comet nuclei in a huge shell surrounding the Sun and planets. B) A large belt containing asteroids in a gap between the orbits of Mars and Jupiter. C) A disklike swarm of icy objects that lies from near the orbit of Neptune to past Pluto's orbit. D) An enormous aggregate of gas and dust from which the Solar System was formed.

C) A disklike swarm of icy objects that lies from near the orbit of Neptune to past Pluto's orbit.

What are Apollo asteroids? A) Asteroids that the Apollo astronauts brought back with them from their trips to the Moon. B) Asteroids near the sun (named for the ancient Greek sun god, Apollo). C) Asteroids with orbits that bring them into the inner Solar System and across Earth's orbit. D) Asteroids that are made primarily of gold.

C) Asteroids with orbits that bring them into the inner Solar System and across Earth's orbit.

The existence of asteroids is supporting evidence of the solar nebula hypothesis, in that A) The asteroids are probably fragments of planetesimals. B) inner belt asteroids are richer in silicate and iron materials and contain fewer carbon-rich materials. C) Both A and B. D) Neither A or B.

C) Both A and B.

What is a meteoroid? A) A glowing trail of hot gas and debris heated by friction as an object moves through the atmosphere. B) A space rock that survives its fall through the Earth's atmosphere and reaches the ground. C) The object that causes a "shooting star," but before it passes through the atmosphere. D) Any one of the large, rocky bodies that orbit the Sun, primarily between Jupiter and Saturn.

C) The object that causes a "shooting star," but before it passes through the atmosphere.

What are the three broad categories of meteorites? A) small, medium and large. B) organic, inorganic, vegetal C) iron, stony, stony-iron. D) red, yellow and blue.

C) iron, stony, stony-iron.

A comet's tail A) is gas and dust pulled off the comet by the Sun's gravity B) always trails behind the comet. C) is gas and dust expelled from the comet's nucleus by the Sun's heat and radiation pressure, and always points away from the Sun. D) is composed mainly of captured particles from the solar wind.

C) is gas and dust expelled from the comet's nucleus by the Sun's heat and radiation pressure, and always points away from the Sun.

What evidence to we have that an impact played a role in the extinction of the dinosaurs? A) The dinosaurs, as well as large numbers of other animals and plants, disappeared rather suddenly. B) There is iridium (rare on Earth, but abundant in meteors) and soot (evidence of wide spread fires) in a layer of clay laid down 65 million years ago. C) Astronomers have found evidence for a 65-million-year-old impact crater in the Yucatan. D) All of the above.

D) All of the above.

How do we know what asteroids are made of? A) Astronomers have studied meteorites that originated in the asteroid belt. B) Astronauts have landed on the asteroid Ceres and brought back rock samples from it. C) The spectrum of sunlight reflected from an asteroid shows absorption features, from which we can determine its composition. D) Both a and c.

D) Both a and c.

Most asteroids are found in the asteroid belt, which lies between the orbits of A) Earth and Mars. B) Saturn and Jupiter. C) Venus and Earth. D) Mars and Jupiter.

D) Mars and Jupiter.

The main asteroid belt lies between the orbits of A)... Earth and Mars. B)... Saturn and Jupiter. C)... Venus and Earth. D)... Mars and Jupiter. E)...Pluto and the Oort cloud..

D)... Mars and Jupiter.

The bright streak of light we see when a meteoroid enters our atmosphere is caused by A)...sunlight reflected from the solid body of the meteoroid. B)... radioactive decay of material in the meteoroid. C)... a process similar to the aurora that is triggered by the meteoroid's disturbing the Earth's magnetic field. D)... frictional heating as the meteoroid speeds through the gases of our atmosphere. E)... the meteoroid's disturbing the atmosphere so that sunlight is refracted in unusual directions.

D)... frictional heating as the meteoroid speeds through the gases of our atmosphere.

Astronomers think that most comets come from A)... interstellar space. B)...material ejected by volcanic eruptions on the moons of the outer planets. C)... condensation of gas in the Sun's hot outer atmosphere. D)... small icy bodies in the extreme outer parts of the Solar System that are disturbed into orbits that bring them closer to the Sun. E)... luminous clouds in the Earth's upper atmosphere created when a small asteroid is captured by the Earth's gravitational force.

D)... small icy bodies in the extreme outer parts of the Solar System that are disturbed into orbits that bring them closer to the Sun.

The tail of a comet A).. is gas and dust pulled off the comet by the Sun's gravity. B)..always points away from the Sun. C).. trails behind the comet, pointing away from the Sun as the comet approaches it, and toward the Sun as the comet moves out of the inner Solar System. D)..is gas and dust expelled from the comet's nucleus and blown outward by radiation pressure and the solar wind. E).. both (b) and (d).

E).. both (b) and (d).