... One of the nearer supernovas of recent years was discovered last month in the bright nearby galaxy M100. The supernova, dubbed SN 2006X, is still near its maximum brightness and visible with a telescope.. ... Comets bright enough to be visible to the unaided eye appear only every few years. Right now, however, a new comet has brightened unexpectedly and is visible as a faint streak to the unaided northern observer in the eastern morning sky just before sunrise. ... In most places on Earth.. ...