Our Milky Way galaxy is a big place. Even at this blazing speed, it takes the sun approximately 225-250 million years to complete one journey around the galaxy’s center.
This amount of time – the time it takes us to orbit the center of the galaxy – is sometimes called a cosmic year.
By the way, in the past when we’ve talked about this subject, people have commented on the difference between the words rotate and revolve. The word revolve means to orbit around another body. Earth revolves (or orbits) around the sun. The sun revolves around the center of the Milky Way galaxy.
On the other hand, rotate means to spin on an axis. The Earth rotates every 24 hours. The sun rotates, but not at a single rate across its surface. The movements of the sunspots indicate that the sun rotates once every 27 days at its equator, but only once in 31 days at its poles.
The planets in our solar system orbit (revolve) around the sun, and the sun orbits (revolves) around the center of the Milky Way galaxy. We take about 225-250 million years to revolve once around the galaxy’s center. This length of time is called a cosmic year.
Credit : Earth Sky
Picture Credit : Google
