The Milky Way Galaxy

The Milky Way is a barred spiral galaxy containing hundreds of billions of stars, including our Sun. It's a massive structure, roughly 100,000 to 180,000 light-years in diameter, with a central bulge and spiral arms extending outwards. Our solar system resides on one of these arms, about 27,000 light-years from the galactic center

How Did They Know The Shape Of Our Galaxy?

The first clue to the shape of the Milky Way comes from the bright band of stars that stretches across the sky (and, as mentioned above, is how the Milky Way got its name). This band of stars can be seen with the naked eye in places with dark night skies. That band comes from seeing the disk of stars that forms the Milky Way from inside the disk, and tells us that our galaxy is basically flat. Several different telescopes, both on the ground and in space, have taken images of the disk of the Milky Way by taking a series of pictures in different directions – a bit like taking a panoramic picture with your camera or phone. The concentration of stars in a band adds to the evidence that the Milky Way is a spiral galaxy. If we lived in an elliptical galaxy, we would see the stars of our galaxy spread out all around the sky, not in a single band