Our Galactic Home

The Milky Way is a barred spiral galaxy roughly 100,000 light-years across. It holds 100 to 400 billion stars, along with vast clouds of gas and dust, billions of planets, and a supermassive black hole at its center. The band of light you see on clear dark nights is our edge-on view of the galaxy's disk, seen from inside it.

The Sun orbits the galactic center at about 230 km/s, taking roughly 225 million years to complete one orbit — a period sometimes called a galactic year. In its 4.6-billion-year life, the Sun has completed about 20 orbits.