A year on a galactic scale
The time the Sun takes to complete one orbit around the centre of the Milky Way is often called a galactic year. NASA gives a duration of about 230 million years and an average Solar System speed of about 720,000 kilometres per hour. These are reference values, not the reading of a perfect clock.
What holds the galaxy together?
The Sun’s motion is affected by the gravity of matter distributed throughout the Milky Way. A supermassive black hole lies at the centre, but it would be incorrect to attribute the gravity determining the Sun’s motion to that black hole alone.
A shared journey
Planets, moons and other bodies continue to move within the Solar System while it travels through the galaxy. Nearby stars also follow galactic orbits, but they do not all move at exactly the same speed.