Comets Quiz

Comets are often called 'dirty snowballs' because they are composed of a mixture of ice, dust, and rock.

The Oort Cloud, a theoretical sphere of icy bodies surrounding our solar system, is believed to be the source of long-period comets, while short-period comets are thought to originate from the Kuiper Belt, a disk of icy bodies beyond Neptune.

The nucleus is the solid, core part of a comet. It's typically a few kilometers to tens of kilometers in diameter and contains the ice, rock, and dust that make up the comet.

When a comet gets close to the Sun, solar radiation causes the ice in the nucleus to sublimate (turn directly from solid to gas). This creates a cloud of gas and dust around the nucleus called the coma.

The solar wind and radiation pressure from the Sun push the gas and dust away from the comet, causing its tail to always point away from the Sun, regardless of the comet's direction of travel.

The ion tail often appears blue because it is composed of ionized gas, which glows in the presence of solar radiation. Specifically, the presence of ions like CO+ (ionized carbon monoxide) is a major contributor to the blue color.

The coma is the term used to describe the atmosphere of gas and dust that surrounds the nucleus of a comet as it approaches the Sun.

When the Earth passes through the trail of dust and debris left behind by a comet, the particles enter our atmosphere and burn up, creating a display of meteors known as a meteor shower.

Halley's Comet is arguably the most famous comet in history. Its predictable orbit has allowed it to be observed and recorded for thousands of years.

The dust tail is made of dust particles pushed away by solar radiation, and the ion (or gas) tail is made of ionized gas pushed away by the solar wind. They often point in slightly different directions.