Starry, starry night? Not really. What appears to be stars or galaxy clusters in this picture are actually black holes colored to identify specific energy levels. This is how the sky may look if you had x-ray vision. The National Aeronautics and Space Administration's (NASA) orbiting Chandra X-Ray Observatory took most of the black holes pictured here in the constellation Bootes. The inset image of the dark side of the moon is shown for size reference.
Black holes are dead stars that collapsed into themselves. They are hundreds of millions of times more massive than the sun and suck everything around them like a vacuum cleaner---even light.