Hub of beauty

When Galileo first turned his telescope to the sky, almost exactly 400 years ago, he could not possibly have known what he was starting. Today, four centuries later, we've come a long, long way. To celebrate the anniversary of Galileo's telescopic revolution, NASA's Great Observatories -- Hubble, Spitzer, and Chandra -- have released a jaw-dropping mosaic of the very heart of the Milky Way galaxy. Behold!