... This popular group is famous as the Leo Triplet - a gathering of three magnificent galaxies in one field of view. ... Is the continent at the end of the Earth slowly melting? ... Unexpected Comet Pojmanski Now Visible . ... Comets bright enough to be visible to the unaided eye appear only every few years. ... Peering deep inside Centaurus A, the closest active galaxy to Earth, the Spitzer Space Telescope's penetrating infrared cameras recorded this startling vista in February 2004. ...