Chapter 14
About what percent of all asteroids are S-type asteroids?
15%
Pluto's bulk density is:
2,100 kg/m3, similar to Callisto's mix of rock and ice.
About what percent of all asteroids are C-type asteroids?
75%
The nucleus, or main solid body, of a comet has a typical size of:
A few kilometers
What is so unusual about Pluto's orbit?
It is more inclined to the ecliptic than any of the eight planets.
From its orbit, we now recognize Pluto as one of the largest members of the:
Kuiper Belt.
The two names most associated with the discovery of Pluto are
Lowell and Tombaugh.
The NASA orbiter that ultimately landed on the surface of the asteroid Eros was:
NEAR shoemaker
What is the defining property of the Trojan asteroids?
They have orbits at the distance of Jupiter and 60 degrees ahead of or behind it.
Pluto is most similar to:
Triton
Which asteroid did Dawn visit first and which is second in its planned mission?
Vesta, Ceres
What is the typical size of most known asteroids?
a few kilometers
Large meteoroids are thought to collide with Earth:
a few times in every million-year period.
The tail of a comet always points:
away from the Sun and becomes longest and brightest at perihelion
What are Dactyl, Gaspra, Mathilde, Eros, and Ida?
four asteroids that have been explored by spacecraft
The orbits of most comets:
lie almost entirely beyond the orbit of Neptune.
The orbits of most asteroids:
lie entirely beyond the orbit of Mars.
Which of the following gives direct information about the age of the solar system?
meteorites from asteroidal debris
Pluto's density is most similar to:
moons of the jovian planets.
Long period comets are thought to reside mainly in the:
oort cloud
Iron meteorites are believed to come from:
the core of a dense M-type asteroid, now broken up.
The Oort Cloud is thought to be:
the spherical cloud of comets and some larger icy bodies surrounding the outer solar system.
Meteorites are valuable to astronomers because:
they may provide evidence about the process in which the solar system was born.
