... The almost familiar scene depicted in this artist's vision of the surface of Saturn's largest moon looks across an eroding landscape into a stormy sky. MESSENGER at Mercury . ... On March 17, the MESSENGER spacecraft became the first to orbit Mercury, the solar system's innermost planet. This is its first processed color image since entering Mercury orbit. ... NGC 5584: Expanding the Universe . ... Kepler s Suns and Planets . ... T Tauri and Hind s Variable Nebula . ... March 2011 . ...