Learn About the Milky Way

The word galaxy comes from the Greek word meaning "milky circle" or, more familiarly, "milky way." The white band of light across the night sky that we call the Milky Way was poetically described long before Galileo. But with his small telescope, what he discovered was a multitude of individual stars, "so numerous as almost to surpass belief."

Today we know that the Milky Way is our home galaxy-a vast rotating spiral of gas, dust, and hundreds of billions of stars. The Sun and its planetary system formed in the outer reaches of the Milky Way about 4.5 billion years ago.  More >

The Milky Way
NASA's Chandra Notices the Galactic Center is Venting
Learn More





  • Field Guide to the Milky Way
    The Milky Way is our home galaxy - a vast rotating spiral of gas, dust, and hundreds of billions of stars.
  • Milky Way Galaxy Q&A
    Questions and answers on the Milky Way Galaxy from our web site visitors
  • Infographic
    The Milky Way is not an island universe,but a member of a small cluster of galaxies called the Local Group.
  • Virtual Tour of the Milky Way
    A new visualization provides an exceptional virtual trip - complete with a 360-degree view - to the center of our home galaxy, the Milky Way.
  • The Galactic Center
    A panoramic X-ray view, covering a 900 by 400 light year swath, shows that the center of the Galaxy is a teeming and tumultuous place.
  • Locating Historic Supernovas in the Milky Way
    Explore the approximate positions and names of historical supernovas in the Milky Way in this simple Flash map.