*Description*:> NASA's Hubble Space Telescope Imaging Spectrograph took a series of snapshots of Saturn's aurora dancing in the sky. The ultraviolet images were taken on Jan. 8, 2004. This dissolve sequence shows the aurora appearing as a ring of light circling the planet's polar ring. Collisions with atoms and molecules make the gases in the planet's atmosphere glow in visible, ultraviolet, and infrared light. Technical facts about this news release: About the Object Object Name: Saturn Object Description: Planet Distance: The semi-major axis of Saturn's orbit about the sun is 9.5 Astronomical Units (A.U.) or roughly 1.4 billion km. Dimensions: The planet (without rings) has a diameter of roughly 75,000 miles (120,000 km) at the equator. About the Data Data Description: The Hubble image was created from HST ACS data from proposal 9354: E. Karkoschka and M. Tomasko (Univ. of Arizona) and STIS data from proposal 10083: J.T. Clarke (Boston Univ.) and collaborators. The science team includes J.T. Clarke (Boston Univ.), J.-C. Gerard and D. Grodent (Univ. de Liege), S. Wannawichian (Boston Univ.), J. Gustin (Univ. de Liege), J. Connerney (NASA Goddard Space Flight Center), F. Crary (Southwest Research Institute), M. Dougherty (Imperial College, London), W. Kurth (Univ. of Iowa), S.W.H. Cowley and E.J. Bunce (Univ. of Leicester), T. Hill (Rice Univ.) and J. Kim (Yonsei Univ., Seoul, Korea) Instrument: ACS/HRC STIS Exposure Date(s): March 22, 2004 January 24, 26, 28, 30, 2004 Filters: F439W ("B"), F502N ([O III]), F550W ("V"), F658N (H-alpha) 25MAMA (Near-UV) and F25SRF2 (Far-UV) About the Image Image Credit: NASA, ESA, J. Clarke (Boston University) and Z. Levay (STScI) Release Date: February 16, 2005 Orientation: Saturn Aurora January 24, 2004 [ http://imgsrc.hubblesite.org/hu/db/2005/06/images/b/formats/compass_large_web.jpg ] *News Release Number:*: STScI-2005-06f