... Dark Spots on Neptune . ... Particularly interesting sources include a bright open cluster of stars and several energetic star-forming regions. ... Phobos: Doomed Moon of Mars . ... Centaurus A: X Rays from an Active Galaxy . ... Its core hidden from optical view by a thick lane of dust, the giant elliptical galaxy Centaurus A was among the first objects observed by the orbiting Chandra X-ray Observatory. ... Mars: 3 D Dunes . ... A Piece of Interplanetary Dust . ...