Minor Bodies - Astronomy

What does Pluto most resemble?

A comet

How big an object causes a typical shooting star?

A grain of sand or a small pebble

A bit of matter that enters Earth's atmosphere and survives to reach the ground is called what?

A meteorite

If there are at least a million asteroids, how did spacecraft like Galileo survive their trip through the asteroid belt?

Although there are many asteroids, they are widely spaced

One of the key reasons professional astronomers today are interested in comets is that they...

Are icy pieces left over from the time that our solar system formed that can give us clues about that early time

What has characteristics most similar to planetesimals?

Asteroids

Why were asteroids not discovered until the 19th century?

Asteroids are generally small compared to planets and require a good telescope and patient searching to spot them

More than 75% of the known asteroids...

Can be found in a belt between Mars and Jupiter

The first asteroid to be discovered (which is also the largest one) is called what?

Ceres

Which are the major steps of solar system formation in the correct order?

Collapse, Accretion, Condensation

What originates from the Kuiper Belt?

Comets

About how often does a 1 km object strike Earth?

Every million years

The best method by which we could protect ourselves from an asteroid impact is by what?

Gently move them out of the way

The main difference between asteroids and comets is that asteroids are mostly composed of rock and comets are mostly composed of what?

Ice

When do comets generally form a tail?

Inside of Jupiter's orbit

What would happen if a 1 km object struck Earth?

It would cause widespread devastation and climate change

Why do astronomers today think that we have an asteroid belt and not a planet between Mars and Jupiter?

Jupiter's gravity prevented material from getting together

Which are thought to have formed farthest from the Sun?

Kuiper Belt Comets

Which have the most elliptical and tilted orbits?

Kuiper Belt Objects

Which of the following is a disk-shaped cloud of icy bodies believed to extend from about 40 AU out to 100 AU? It is believed that short period comets originate from this region.

Kuiper belt

The asteroid belt lies between the orbits of which two planets?

Mars and Jupiter

Astronomers estimate that there may be a trillion comet nuclei orbiting beyond Pluto. Why then do we not see more comets in our skies?

Most comets remain in stable orbits far beyond Pluto; only a few had their orbits disturbed, bringing them into the inner solar system

Jupiter nudges the asteroids through the influence of what?

Orbital resonances

The comet that broke into more than 20 pieces and then collided with Jupiter in 1994 was what?

Shoemaker - Levy 9

The large reservoir of comet nuclei far beyond Pluto, from which we believe new comets come into the inner solar system, is called what?

The Oort Cloud

According to astronomical tradition, who gets to suggest the name for a newly discovered asteroid?

The discoverer of the asteroid

Which part of a comet is the densest?

The nucleus

Can an asteroid be pure metal?

Yes, it must have been the core of a shattered asteroid