The Milky Way
100,000light-years across
Our galaxy is about 100,000 light-years across and contains somewhere between 100 and 400 billion stars. Light that left one edge when our species first appeared still hasn't reached the other side.
▶ Fly out to the galaxy in the Cosmic Zoom
Our city of stars
The Milky Way is a barred spiral galaxy. The Sun sits about 26,000 light-years from the centre — out in the quiet suburbs — and orbits the galactic core once every ~230 million years. The last time we were on this side of the orbit, dinosaurs were only just appearing. At the centre lies Sagittarius A*, a black hole of about four million solar masses.
Every star you have ever seen with your naked eye — every constellation, every point of light in every night sky in human history — lives within roughly a thousand light-years of Earth: about 1% of the way across this one galaxy.
The Milky Way by the numbers
Diameter
≈ 100,000 light-years
Stars
100–400 billion
Sun’s distance from centre
≈ 26,000 light-years
One galactic orbit
≈ 230 million years
Central black hole
≈ 4 million solar masses
Next big event
Andromeda merger, ~4.5 billion yr
The Cosmic Zoom takes you there: from the solar system out through the nearest stars until the whole spiral fills your view — then keeps going.
Keep going
✓ Facts verified July 2026
Every figure on this page is a real, rounded value checked against primary sources. Found something out of date? See how we keep it accurate.