This is how long it takes the sun to go around the galaxy.
Humans are used to keeping time by measuring Earth’s movement relative to the sun. But while Earth’s trips around its star are noteworthy to life on our pale blue dot, that journey is pretty insignificant when compared with the epic voyage that carries the sun — and our entire solar system — around the center of the Milky Way. Orbiting the Milky Way galaxy just once takes the sun approximately 220 million to 230 million Earth years, according to Keith Hawkins, an assistant professor of astronomy at the University of Texas at Austin. In other words, if we were to measure time by this galactic «clock,» Earth would be about 16 years old (in galactic, or cosmic years), the sun would have formed about 20 years ago, and the universe would be just about 60 years old. Related: Does the sun rotate? The solar system’s journey around the galaxy resembles Earth’s orbit around the sun. But rather than orbiting a star, the sun circles the supermassive black hole that lies at the center of the Milky Way and exerts a tremendous amount of gravity on everything in the galaxy, Hawkins said.
