The Sun is not the only star in the Milky Way galaxy. It is one of billions of stars that orbit the galaxy’s center. The Sun’s journey around the galaxy takes a very long time, but it is not impossible to calculate.
What is a Galactic Year?
A galactic year is the amount of time it takes for the Sun to complete one orbit around the center of the Milky Way galaxy. One galactic year is approximately 230 million Earth years.
How Fast Does the Sun Move Around the Galaxy?
The Sun’s speed around the galaxy is about 230 kilometers per second (143 miles per second). That’s fast enough to circumnavigate the Earth’s equator in just 2 minutes and 54 seconds!
The Sun’s Orbit
The Sun’s orbit around the galaxy is not a perfect circle. It is actually an ellipse, or oval shape. The Sun’s distance from the center of the galaxy varies as it travels around. The closest point in the Sun’s orbit is called perihelion, and the farthest point is called aphelion.
The Sun’s speed is also not constant throughout its orbit. It is fastest at perihelion and slowest at aphelion. This is because the Sun is pulled more strongly by the gravity of the galaxy’s center at perihelion than it is at aphelion.
How Long Does It Take?
The length of a galactic year depends on the size of the galaxy. The Milky Way galaxy is about 100,000 light-years across, so it takes the Sun about 230 million years to complete one orbit.
How Many Times Has the Sun Orbited the Galaxy?
The Sun is about 4.6 billion years old. Since one galactic year is about 230 million years, the Sun has orbited the galaxy about 20 times since its formation.
The Sun’s journey around the galaxy is a long and slow one, but it is an important part of the galaxy’s history. The Sun’s orbit helps to keep the galaxy’s stars in their proper places and helps to distribute gas and dust throughout the galaxy.