A rocky object that revolves around the sun, but is too small to be considered a planet.

A chunk of ice and dust whose orbit is usually a long, narrow ellipse

The nucleus, coma, and tail are the three parts of a(n) __________________________.

Gas and dust form a fuzzy outer layer around a comet's head, called a ______________________.

Scientists hypothesize that the dinosaurs became extinct as a result of a large _______________ hitting Earth 65 million years ago.

As a comet approaches the sun, the gas and dust heat up and ____________________________.

Chunks of ice and dust who orbits are usually a long, narrow ellipse.

Which objects are found in the Oort cloud and Kuiper belt?

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

A doughnut-shaped region of comets that extends from beyond Neptune's orbit to about 100 times Earth's distance from the sun.

A spherical region of comets that surrounds the solar system out to more than 1000 times the distance between Pluto and the sun.

A streak of light in our atmosphere is a _____________________.

Which objects are smallest?

Which object is like a "dirty snowball" about the size of a mountain?