Produced by Clark Planetarium
Salt Lake City, Utah
We gaze out at a faint band of light stretching across the night sky; the Milky Way galaxy. Every star we see belongs to the Milky Way. In that giant pinwheel, new stars are forming from clouds of dust and gas, as old stars flash and fade into the darkness. The Milky Way is a spiral galaxy, with a core of old stars and arms of dust, gas and clusters of younger stars. Surrounding the Milky Way is a halo of old stars and a swarm of globular clusters which contain hundreds of thousands of stars.
The Milky Way is one of billions of galaxies that fill the universe around us. Some are spirals like the Milky Way. Others are ellipses or irregular collections of stars. The galaxies themselves belong to groups, which belong to clusters, which belong to super clusters of galaxies. Some interact by colliding or passing nearby one another raising tides and ripping stars from their neighbors.
As we look out into space, we are looking backwards in time. Stars in our own Milky Way galaxy are seen today as they were dozens to hundreds of thousands of years ago. Light from distant galaxies has been traveling across space for millions to billions of years, reaching our eyes in the darkness tonight.