John Spencer's Publications

Some Recent Papers and Preprints

• Io Volcanism Seen by New Horizons: A Major Eruption of the Tvashtar Volcano. J. R. Spencer, S. A. Stern, A. F. Cheng, H. A. Weaver, D. C. Reuter, K. Retherford, A. Lunsford, J. M. Moore, O. Abramov, R. M. C. Lopes, J. E. Perry, L. Kamp, M. Showalter, K. L. Jessup, F. Marchis, P. M. Schenk, C. Dumas 2007. Science 318, 240-243. HTML or PDF format.
• Cassini encounters Enceladus: Background, and the discovery of a south polar hot spot.  J. R. Spencer, J. C. Pearl, M. Segura, F. M. Flasar, A. Mamoutkine, P. Romani, B. J. Buratti, A. R. Hendrix, L. J. Spilker, and R. M. C. Lopes 2006.  Science 311, 1401-1405. HTML or PDF format.
• The nature of Europa's dark non-ice surface material: Spatially-resolved high spectral resolution spectroscopy from the Keck telescope.  J. R. Spencer, W. M. Grundy, C. Dumas, R. W. Carlson, T. B. McCord, G. B. Hansen, and R. J. Terrile 2006.  Icarus 176, 283-304. PDF format (0.6 MB).
• Mid-infrared detection of large longitudinal asymmetries in Io's SO₂ atmosphere. J. R. Spencer, E. Lellouch, M. J. Richter, M. A. Lopez-Valverde, K. L. Jessup, T. K. Greathouse, and J-M. Flaud 2005. Icarus, 176 283-304. PDF format (1.0 MB).
• The atmospheric signature of Io's Prometheus plume and anti-Jovian hemisphere: Evidence for a sublimation atmosphere. K.L. Jessup, J.R. Spencer, G.E. Ballester, R.R. Howell., F. Roesler, M. Vigil, and R. Yelle 2003. Icarus 169, 197-215. PDF format (1.2 MB).
• Mapping of Io's Thermal Radiation by the Galileo Photopolarimeter-Radiometer (PPR) Instrument. J. A. Rathbun, J. R. Spencer, L. K. Tamppari, T. Z. Martin, L. Barnard, and L. D. Travis 2003, Icarus 169 127-139. PDF format.
• Condensed O₂ on Europa and Callisto. J. R. Spencer and W. M. Calvin 2002, Astron. J. 124, 3400-3403, 2002. PDF format.
• Loki, Io: A periodic volcano. J. A. Rathbun, J. R. Spencer, A. G. Davies, R. R. Howell, and L. Wilson 2002. Geophys. Res. Lett. citation number 1443. PDF format.
• Ground-based observations of volcanism on Io in 1999 and early 2000. Howell, R.R., J.R. Spencer, J. D. Goguen, F. Marchis, R. Prange, T. Fusco, D.L. Blaney, G.J. Veeder, J.A. Rathbun, G.S. Orton, A.J. Grocholsky, J.A. Stansberry, G.S. Kanner, E.K. Hege (2001). J. Geophys. Res. 106, 33129-33139.
• Discovery of Gaseous S₂ in Io's Pele Plume, Science 288, 1208-1210, 2000.
  Full HTML Version | PDF Version | Abstract
• Io's thermal emission from the Galileo Photopolarimeter-Radiometer, Science 288, 1198 - 1201, 2000.
  Full HTML Version | PDF Version | Abstract
• Temperatures on Europa from Galileo PPR: Nighttime Thermal Anomalies. J.R. Spencer, L.K. Tamppari, T.Z. Martin, and L.D. Travis. Science, 284, 1514 - 1516, 1999. Reprints available on request.
• Upper Limits to the Depth of Condensed O2 Absorption Bands on the Icy Saturnian Satellites and Saturn's Rings (now published in Icarus 136, 349-352, 1998).
• The Pele Plume (Io): Observations with the Hubble Space Telescope (now published in Geophys. Res. Lett. 24, 2471-2474, 1997)
• A History of High-Temperature Io Volcanism, February 1995 to May 1997 (now published in Geophys. Res. Lett. 24, 2451-2454, 1997).
• Volcanic Resurfacing of Io: Post-Repair HST Imaging Icarus 127, 221, 1997.