Journey Through the Solar System

Welcome to your home in space — the solar system. Our journey starts here, at the Sun. It's not solid ground or fire like a campfire — it's a colossal ball of glowing plasma, so big that a million Earths could fit inside. And it holds almost all the mass in the whole solar system. Its gravity is the invisible string that keeps every planet swinging around it, year after year.

Closest to the Sun are the four rocky worlds. Tiny Mercury, scorched and cratered. Venus, wrapped in thick poison clouds. Then our own blue Earth, with its single Moon — the only world we know with life. And rusty red Mars, with the biggest volcano in the solar system. Four small planets made of rock and metal, all huddled close to the Sun's warmth.

Past Mars, we reach the asteroid belt — a wide ring of leftover rubble from when the planets were forming. There are millions of asteroids here, from pebbles to one dwarf planet, Ceres, hundreds of kilometres across. But don't picture a crowded video-game field. The belt is so enormous and so spread out that our spacecraft fly straight through it without hitting a thing.

Now things get big. This is Jupiter — the king of the planets. It's a gas giant, so massive that all the other planets could fit inside it with room to spare. Those stripes are roaring bands of cloud, and that swirl is the Great Red Spot — a storm wider than our entire planet that has raged for centuries. Jupiter has more than ninety moons. Watch its four biggest circle it, just like Galileo saw four hundred years ago.

And here is the jewel of the solar system — Saturn. Those breathtaking rings aren't solid. They're billions and billions of chunks of ice and rock, from grains of sand to whole houses, all orbiting Saturn in a shimmering disc. The rings stretch nearly the distance to our Moon — yet they're only about ten metres thick. If you shrank Saturn to a basketball, the rings would be thinner than a sheet of paper.

Far, far out in the cold and the dark are the two ice giants. Uranus is the strange one — it's tipped completely onto its side, so it rolls around the Sun like a ball. And deep blue Neptune, the most distant planet, has the fastest winds in the solar system — storms screaming faster than a jet plane. Out here, the Sun is just a bright star, and a single year lasts longer than a human lifetime.

Let's pull all the way back and see it together. Eight planets — four small and rocky, four giant — a belt of rubble in between, and hundreds of moons, all tracing their great circles around one star. This is our solar system. Our neighbourhood in the universe. And that ordinary yellow star at the centre? It's the thing that makes all of it — including you — possible.