Chapter 9 Quiz
Which statement is not true?
-
How many moons is Pluto known to have?
3
How do asteroids differ from comets?
Asteroids are made of rocky material. Comets are made of icy material.
Why do asteroids and comets differ in composition?
Asteroids formed inside the frost line, while comets formed outside.
What is Charon thought to have in common with our own Moon?
Both probably formed as a result of giant impacts.
Which statement is not thought to be true of all comets?
Comets are always followed by long tails.
Suppose we discover a new comet on an orbit that brings it closer to the Sun than Mercury every 125 years. What can we conclude?
It has been on its current orbit for only a very short time compared to the age of our solar system.
According to the nebular theory, how did the Oort cloud form?
It is made of planetesimals formed in the outer solar system that were flung into distant orbits by encounters with the jovian planets.
Suppose there were no solar wind. How would the appearance of a comet in our inner solar system be different?
It would have only one tail instead of two.
Pluto is different from the Jovian planets in all of the following ways except which one?
Its surface temperature is very cold.
What do asteroids and comets have in common?
Most are unchanged since their formation in the solar nebula.
Which of the following is not a piece of evidence supporting the idea that Pluto is a large comet of the Kuiper belt?
Pluto grows a coma and a long tail when it is at the point in its orbit closest to the Sun.
What happened in the Deep Impact mission?
The impactor created a small crater on the comet.
What is a meteorite?
a fragment of an asteroid from the solar system that has fallen to Earth's surface
A rock found on Earth that crashed down from space is called
a meteorite.
The total number of comets orbiting the Sun is estimated to be about
a trillion.
Where are the Trojan asteroids located?
along Jupiter's orbit, 60° ahead of and behind Jupiter
A rocky leftover planetesimal orbiting the Sun is
an asteroid
How was Pluto's surface mapped?
by measuring the change in brightness as Charon eclipsed Pluto
Processed meteorites with high metal content probably are
chunks of a larger asteroid that was shattered by a collision.
Comets with extremely elliptical orbits, like comets Hyakutake and Hale-Bopp,
come from the Oort cloud.
Where did comets that are now in the Kuiper belt originally form?
near the radius at which they orbit today
In the impact theory of the extinction of the dinosaurs some 65 million years ago, the dinosaurs died off largely because
of global climate effects initiated by dust and smoke that entered the atmosphere after the impact.
On average, how often do impactors about 10 km in size, large enough to produce mass extinction, hit Earth?
once every hundred million years
A typical shooting star in a meteor shower is caused by a ________ entering Earth's atmosphere.
pea-size particle from a comet
Rather than being a planet, Pluto is really just a large member of
the Kuiper belt.
When a comet passes near the Sun, part of it takes on the appearance of a large, bright ball from which the tail extends. This part is called
the coma
What was the Shoemaker-Levy 9 impact?
the impact of a fragmented comet on Jupiter, carefully observed by astronomers when it occurred in 1994
What part of a comet points most directly away from the Sun?
the plasma tail
