Astronomy Picture of the Day . ... Until the invention of the telescope, nobody really knew what the "Milky Way" was. Pluto: The Frozen Planet . ... Seen from the Pik Terskol Observatory in the northern Caucasus mountains, comet Hale-Bopp and the bright stars of the constellation Perseus hang above the snowy, moon-lit landscape. Although it reminds Northern Hemisphere dwellers of an idyllic Winter scene, this picture was actually recorded in the spring - on April 13th of this year. ... April . ...