Comet Streaking Through Space Coloring Page: Free PDF

Comets and Their Sweeping Tails

A Dirty Snowball From the Solar System's Edge

Astronomers sometimes describe a comet's core, or nucleus, as a "dirty snowball" - a bumpy, irregular chunk of ice, dust, and frozen gases usually only a few miles across, much like the round textured shape in this coloring page. Most comets originate far beyond Neptune, in a distant, disc-shaped region called the Kuiper Belt or an even more distant shell called the Oort Cloud, before gravity nudges one onto a long path toward the inner solar system.

Because comet nuclei are so small and dark, they are usually invisible until they get close enough to the sun for their ice to begin turning directly into gas, a process that creates the glowing head and tail that make comets so recognizable from Earth.

Why the Tail Always Points Away From the Sun

As a comet nears the sun, solar heat vaporizes its surface ice, releasing gas and dust that form a glowing cloud around the nucleus called a coma, which can grow larger than the planet Jupiter. Solar wind and radiation pressure then push that released material into a long tail that always streams away from the sun, regardless of which direction the comet itself is traveling - meaning a comet heading toward the sun and one heading away can both have tails pointing the same general direction at the same moment.

Many comets actually have two separate tails: a straighter, bluish ion tail made of charged gas particles pushed directly by solar wind, and a curved, whiter dust tail made of larger particles that drift more slowly, together creating the sweeping, layered look captured in illustrations like this one.

Comets That Return on a Schedule

Some comets swing past the sun only once before being flung back into deep space, but others settle into predictable orbits and return again and again. Halley's Comet is the most famous example, visible from Earth roughly every 76 years, with recorded sightings stretching back over 2,000 years across multiple ancient civilizations, including a depiction on the Bayeux Tapestry commemorating its 1066 appearance.

Each close pass by the sun causes a returning comet to lose a small amount of its ice and dust to space, meaning that after enough orbits, a comet can eventually break apart entirely or shrink into a much smaller, less active object, which is part of why comet tails and comas fade the further a comet drifts from the sun.

Comets and the Story of Earth's Water

Some scientists believe comets may have delivered a portion of Earth's water and organic molecules billions of years ago, when far more comets and asteroids collided with the young planet during a period known as the Late Heavy Bombardment. Spacecraft missions such as ESA's Rosetta, which orbited and landed a probe on a comet in 2014, have directly sampled comet ice to compare its chemistry with Earth's oceans, refining scientists' understanding of exactly how much comets may have contributed.

Meteor showers on Earth are another direct link to comets - many annual showers happen when Earth passes through a trail of dust left behind by a comet's previous orbit, with each speck burning up as a streak of light in the night sky, a smaller nightly echo of the larger comet still sweeping through space.