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This beautiful wide-angle view of the Milky Way contains three other fuzzy celestial citizens. Most prominent is the splendid tail of comet McNaught (2008), caught as it passed through the inner solar system spewing out the dust and gas that glistens in the sunlight. Just above the comet you can see the Large and Small Magellanic Clouds. These are two dwarf galaxies that are within the grasp of our galaxy's gravitational field, held as part of its entourage of small galaxy companions.
But the most striking feature in this image is the majestic disk of our own galaxy - the Milky Way - stretching across the sky. Of course, it doesn't look like a disk because we're inside it, so from our viewpoint it looks like a band all around the sky. The combined light from several billion distant stars makes the milky light, while huge rarefied clouds of gas and obscuring dust break the band into patches. The entire system is about 80 thousand light years across and 1000 light years thick, with us located 25,000 light years from its center. One way to consider the Milky Way is as our "hometown." Just as you might be born, live out your life, and die in a single city, so the sun has been born, lives out its life, and will die, within the Milky Way galaxy. Our galaxy is a giant city of stars, one among many, each providing a complex and nurturing environment within which billions of stars live out their lives. So when you next look up to see this band of milky light, try to feel that sense of belonging that you might feel for your own hometown. The Milky Way is really your cosmic hometown. (Image by Miloslav Druckmuller) |