PhyFl18ss1.2.4 So even Galileo and Newton assumed that the sun was not moving. Well . . . turns out it moves at around 500,000 mile per hour on its journey around the Super Massive Black Hole at the center of the Milky Way Galaxy. A Galactic Year is how long it takes the sun to go around once. Since our solar system is around 4,500,000,000 years old that means we are somewhere in the neighborhood of 18 galactic years old. Still teenagers! When we were 17, there were dinosaurs walking around the Earth.