Solar System Coloring Page: Free Printable PDF Sheet

The Sun, the Planets, and Our Solar System

A Star at the Center

The sun is not a planet at all but a star, an enormous ball of hydrogen and helium gas so large that more than one million Earths could fit inside it. Its gravity is strong enough to hold every planet, moon, comet, and asteroid in the solar system in orbit around it, even objects more than three billion miles away in the outer darkness beyond Neptune.

Sunlight takes about eight minutes to travel from the sun's surface to Earth, which means every sunbeam warming a backyard actually left the sun eight minutes earlier. The sun has been burning for about 4.6 billion years and has enough fuel left to keep shining for roughly another five billion years before it changes into a different kind of star entirely.

Eight Planets, Eight Personalities

Mercury and Venus are the two innermost planets, both rocky worlds with no moons, while Earth is the only planet known to support life as far as scientists have discovered. Mars, the fourth planet, has a thin, dusty atmosphere and is home to the tallest known volcano in the solar system, Olympus Mons, which stands nearly three times taller than Mount Everest.

Beyond Mars sit the gas giants Jupiter and Saturn, both so large they could each swallow more than 1,000 Earths, followed by the icy giants Uranus and Neptune, which are made largely of water, ammonia, and methane ices rather than solid rock. Uranus is unusual because it spins almost completely on its side, likely the result of an ancient collision early in the solar system's history.

Rings Around Distant Worlds

Saturn's rings are the widest and brightest in the solar system, stretching roughly 175,000 miles across and made of countless chunks of ice and rock ranging from dust grains to boulder-sized pieces. Jupiter, Uranus, and Neptune all have their own ring systems too, but those rings are much thinner, darker, and harder to see even through a telescope, which is part of why Saturn gets most of the ringed-planet attention.

Astronomers believe planetary rings form when a moon breaks apart from a strong gravitational pull, from leftover material that never clumped into a moon, or from a comet torn apart as it passed too close. Watching how a ring changes shape over centuries helps scientists study the gravity of the planet it circles.

Orbits That Take Years, Not Days

Every planet follows its own oval-shaped path, called an orbit, and the farther a planet sits from the sun, the longer that path takes to complete. Earth circles the sun once every 365 days, but Neptune, the most distant official planet, takes about 165 Earth years to complete a single orbit, meaning it has not finished a full lap since its discovery in 1846.

Lining up the planets by size and distance, the way this coloring page arranges them in a curving row, helps make that huge range of scale easier to picture. A quick lap around the sun for Mercury takes just 88 days, while the outer planets move so slowly that their positions barely shift within a single human lifetime.