Sky Tonight—January 17, Sun moves toward star Vega

Courtesy of EarthSky A Clear Voice for Science Visit EarthSky at www.EarthSky.org An Australia visitor wrote, I seek to find out what speed our sun is traveling at and also how many years does it take to circumnavigate the galaxy? Our Milky Way galaxy is a collection of several hundred billion stars. It has an estimated diameter of 100,000 light-years. Our sun does indeed circumnavigate the Milky Way galaxy. In space, everything moves. There are various estimates for the speed the sun travels ... Full Story