The Milky Way

Our galaxy. On a really dark night you can see it as a pale stripe. Our galaxy — a slowly turning city of a few hundred billion stars, so big that light needs 100,000 years to cross it. Every star you have ever seen with your own eyes lives inside it.

Also called: our galaxy.

🕒 When can I see it?🚀 Travel there

The Milky Way — Drawn, not photographed.

What it is

Our home galaxy: a barred spiral of a few hundred billion stars about 100,000 light-years across, with the solar system tucked into a quiet spur 26,000 light-years from the centre.

Spiral galaxy: A flat disc of stars wound into arms. Ours is one. Every kind of thing there is →

How to find the Milky Way

On a truly dark night, look for a faint band of light crossing the whole sky: that is our own galaxy seen from the inside, edge-on.

The Planetarium works out where it actually is from your own place and the date — including whether it is above the horizon at all tonight.

Show me the Milky Way in tonight's sky

Worth knowing about the Milky Way

What it is: A barred spiral galaxy: a flat, slowly spinning disk of a few hundred billion stars held together by gravity. The Sun takes about 230 million years to go around it once — the last time we were on this side, dinosaurs were new.
The centre: A crowded golden bar of old stars, and at its very middle Sagittarius A* — a black hole with four million times the Sun's mass. The stars closest to it whip around it the way comets whip around the Sun.
The arms: The bright spiral arms are not separate streams of stars — they are traffic jams, places where stars, gas and dust crowd together as they orbit. That is where new stars are being born, which is why the arms sparkle with young blue stars and pink star-forming clouds like the Orion and Eagle nebulae.
Where we live: The whole solar system — Sun, planets, comets, spacecraft and all — sits in the Orion spur, a short side-branch between two major arms, 26,000 light-years from the centre. The quiet suburbs: far from the crowded middle, in between the busy arms.
Dust and clouds: Between the stars drift huge clouds of gas and dust. Some, like the Coalsack, are dark and blot out everything behind them; others glow from the inside because new stars are switching on within.
When stars die: The Crab Nebula and the remnants of Tycho's and Kepler's supernovae are wreckage of exploded stars. Those explosions scatter the ingredients new planets are built from — including the ones you are made of.
Neighbours: Smaller galaxies orbit ours the way moons orbit a planet. The Large Magellanic Cloud is the biggest of them — close enough that in 1987 one of its stars was seen exploding with the naked eye.