The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the center of the Milky Way Galaxy. One is 230 million years.

How many years are in a galactic year?

Compared with an Earth year, a galactic year represents time on a grand scale — but it's not a consistent measurement across the galaxy. What we Earthlings call a galactic year is specific to Earth's place in the Milky Way's spiral. "We would say that a galactic year is 220, 230 million years.

How many galactic years old is the Earth?

Earth is approximately 4.5 billion years old, which means it has lived through about 20 complete loops around the galaxy.