Distance from center of the Milky Way to solar system:
27,000light years=2.55⋅1017km 1) Time for one turn around the center of the Milky Way:
t=220km/s2π⋅2.55⋅1017km=7.29⋅1015s=231million years2)
Therefore, Earth circled
231million years4.5billion years=19.5 times.
Comments