Astronomy Picture of the Day . ... A Galactic Mushroom Cloud . ... The Orion Nebula from Subaru . ... Some stars in the Trapezium, an open cluster of stars at the center, are only visible in infrared light. ... Welcome to Planet Earth . ... The Earth is shaped like a sphere and composed mostly of rock. ... The Moon In January . ... The Galactic Center A Radio Mystery . ... A premier high resolution view, this startlingly beautiful picture covers a 4x4 degree region around the galactic center. ...