- from Galaxies
Circling around the center of the Milky Way is like being on a merry-go-round that never stops. Our view of the universe changes all the time. But it changes very slowly! One complete circle takes 225 million years. The last time Earth was in the same place as it is now in our galaxy, the age of dinosaurs had just begun!
We can’t see the whole galaxy from our spot in the Milky Way. We learn about its shape from what we can see. We also learn by comparing it to other galaxies. What does the Milky Way look like from far away? It has corkscrew-shaped arms that spin out from a bar in the center. That’s called a barred spiral. From the side, the Milky Way looks like the edge of a plate. A round halo of stars sticks out above and below the center of the plate. We can’t see our galaxy’s core, or nucleus. Our view is blocked by stars and gas clouds. Also in the way are dust rings and star clusters. There’s much more to the Milky Way than our eyes can see.