Comets

In this section we are going to talk about comets and where they come from.

_{Image courtesy of NASA / JPL-Caltech / R. HurtOriginal text courtesy of NASA / JPL-CaltechSVG conversion by Holek / Public domain}

Comets are bodies made mostly of ice. They are drawn in by the Sun’s gravity to the center of the solar system. Their orbits are highly elliptical. There are two type of comets in our solar system. Short-Period comets come from the Kuiper Belt. This is a region past Neptune’s orbit. There are two dwarf planets there. Short-Period comets take 200 years or less to orbit the Sun. dxLong-Period comets may take thousands or millions of years to orbit the sun. Where do these comets come from? They come from the Oort Cloud. The Oort Cloud is a region of space 50,000-100,000 AU from the Sun. (One Astronomical Unit(AU) is the distance from the Earth to the Sun.) Unlike the Kuiper Belt, the Oort Cloud is shaped like a hollow sphere. It encompasses the entire solar system, like a hollow ball with a tiny object in the center.