Milky Way

The Milky Way galaxy, sometimes simply called the galaxy, is a barred spiral galaxy that formed as part of the Local Group, which is an association of approximately 25 galaxies. The word milky came from the band of white light that early astronomers saw in the sky on clear nights. Greek philosopher Democritus (c. 460 BCE–c. 370 BCE) is generally considered the first astronomer to have explained that the Milky Way consisted of a band of stars. Based on examinations of radioactive decay of elements within individual stars, the age of the Milky Way is estimated to be about 13.6 billion years.

On a clear, moonless night, away from the bright lights of the city, the Milky Way galaxy is...