Exam 9: Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Assume that the average rate of 1- km sized asteroids hitting the Earth is about 1 every million years. The chance of the Earth being hit by a 1- km sized asteroid in the next 100 years is about:

Which of the following does not lend support to the idea that Pluto is a Kuiper- belt object?

Briefly describe the evidence suggesting that a 10- km asteroid or comet hit Earth at the time of the dinosaur extinction.

If we could put all the asteroids together, their total mass would be .

According to the nebular theory, how did the asteroid belt form?

Rather than being a planet, Pluto is really just a large member of

An icy leftover planetesimal orbiting the Sun is

A typical shooting star in a meteor shower is caused by a entering Earth's atmosphere.

What are "dwarf planets"?

Pluto's surface features are completely unknown and await the visit by the New Horizon's spacecraft in 2015.

What do we mean by a primitive meteorite?

A rocky leftover planetesimal orbiting the Sun is

Will Pluto eventually collide with Neptune?

Suppose you find a meteorite made almost entirely of metal. According to current science, which of the following statements must be true?

According to the nebular theory, how did the Kuiper belt form?

During the time that a comet passes through the inner solar system, the comet can appear quite bright because

How do asteroids differ from comets?

Primitive meteorites can be distinguished from other meteorites and terrestrial rocks because they

The total number of comets orbiting the Sun is estimated to be about .

A typical meteor is created by a particle about the size of a .