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Our galaxy is a slowly swirling whirlpool of roughly 200 billion stars, spread across 100,000 light-years. From our position 27,000 light-years away from the center the galaxy surrounds us and appears as a cloudy band across the sky, known as the Milky Way. Equally important as the visible stars are gas and dust. Found mostly in the central plane, dark lanes of dust clouds can be seen mottling the bright wash of stars. Together, the stars, gas, and dust weigh as much as a trillion Suns.

The dust blocks our view of distant parts of the galaxy, but a bright area just below center is a window that allows us to see all the way to the central halo of older, more yellow stars. The true center lies behind the dark areas that split the central bulge. The spiral arms are where most star-forming activity is taking place. Glowing red clouds of excited hydrogen mark the presence of young, hot, giant stars. Although most stars are like our Sun, or smaller, they are outshone by the giant and supergiant stars at large distances. All the stars of our constellations are relatively nearby, and only a few are modest stars like the Sun. Many of them are of a similar age, dating from a starbirth episode beginning 30 million years ago. The dinosaurs would have seen different constellations.

Some highlights for stargazers are easily visible in or near the Milky Way. At left and low, at about galactic longitude 180, the bright star Aldebaran marks the eye of the bull, Taurus. Nearby are the Pleiades, a cluster of blue stars below the plane and a little further in from the edge of the panorama. They glow blue because they are blue-white giants. The cluster is surrounded by a thin dust cloud that shines blue from reflected light, and is called a reflection nebula. Just above the Pleiades is a red emission nebula nicknamed the California Nebula, which is glowing because it is energized by nearby hot stars. Hydrogen tends to glow most brightly in the deep red. Here, the camera shows what our eyes miss; at night we see best in the green wavelengths, and in black and white.

Moving further right along the center line we find concentrations of stars, or clusters, and more emission nebulae. Well above the plane, at about galactic longitude 120, is Polaris, the North Star. Directly below the plane is our sister galaxy, M31, or the Andromeda Galaxy. It is about 2 million light-years distant. Next we come to a rich area in the constellation Cygnus. An emission nebula next to the bright star Deneb,along the center line, is known as the North American Nebula, because its shape reminds on of the continent. Above and a little to the right is Vega, one of the three stars of the summer triangle, the others being Deneb and Altair, seen just below the center line in Aquila, at about galactic longitude 50.