One Galactic Year Lasts About 230 Million Years

The Sun and the whole solar system circle the center of the Milky Way once about every 230 million years. That is one galactic year. The last time the solar system stood where it is now on that loop, the first dinosaurs were just appearing on Earth.

The Sun travels at about 828,000 kilometers per hour (514,000 miles per hour) and sits roughly 28,000 light-years from the galactic center. Even at that speed the loop is enormous. Since the Sun formed 4.6 billion years ago it has finished about 20 laps. The combined gravity of the galaxy’s stars, gas and dark matter bends the Sun’s path into this orbit.