NASA Quarterly UVIS Q2 - 2008 (Feb. - Apr. 2008)

UVIS: Accomplishments Science Highlights Enceladus flyby March 12 2008 Obtained UV spectra of north and solar polar regions Continued analysis of the Enceladus occultation data from October 24 (admittedly last quarter, but we didn’t get the reconstructed trajectory until this quarter), and the Rev 61 Enceladus flyby on March 12

UVIS: Science Highlights Streams of high-density gas detected by Cassini’s Ultraviolet Imaging Spectromer (UVIS) on Saturn’s moon Enceladus match the locations of dust jets determined from Cassini images, labeled here with Roman numerals. The spectrograph pinpointed the locations of individual gas streams in the plume in a ‘stellar occultation’ which involves measuring the light of a star, (in this case, zeta Orionis), as it passed behind the plume from Cassini’s viewpoint. The blue line in this projection shows the path of the starlight through the plume,over the south polar region of Enceladus. The instrument looked at the star across this path in the direction indicated by the short blue lines. Some of the dust jets appear to merge together in UVIS stellar occultation data. The dimming of starlight labeled “a” was caused by dust jets V and VII. The dimming of starlight marked as feature “b” is probably off-set too far to be associated with dust jet I, because the jet is not perfectly vertical. Dimming of starlight labeled “c” corresponds to dust jet VI, and “d” is dust jet III, with dust jet II in between. The individual jets come from sources with an area of less than 300 by 300 meters (1,000 feet square) – about the size of half a tennis court -- probably stretched out rectangularly along the tiger stripes. The new UVIS data indicate that the water molecules are blasting off from Enceladus at faster than 600 meters per second (about 1,300 miles per hour.

UVIS: Accomplishments Publications Published this quarter 6 In Press (Went into press Feb-Apr and also includes still in press from earlier quarters) 2 Submitted (Submitted Feb-Apr and also includes submitted earlier and still in review) 4 Published 2008 to date: 8 Published Entire mission 65 Presentations at scientific meetings 2: EGU, 13-18 April, Vienna 2: LPSC, March 2008, Houston, Texas 1: Second Titan Workshop, March 24-26 , Miami, Fl 1: Astrobiology Science Conference, April 14 - 17, Santa Clara, CA Public Outreach and Press Activities 1: Press release 1: Press conference 9: Public Lectures

UVIS: Plans Science Plans (May - Jul 2008) Plans for Enceladus flybys in August and October 2008 Publications (May - Jul 2008) In preparation (includes all papers submitted up to now, but not yet published) 6 1 paper submitted to APJ. 1 paper submitted to JGR-Planets 1 paper submitted to Rev. Geophys 1 paper submitted to Origin of Life and Evolution of Biospheres 1 paper submitted to Astronomy and Astrophysics. 1 paper submited to Scholarpedia. Upcoming presentations at scientific meetings (May - Jul 2008) 2 papers at AGU Joint Assembly in Ft. Lauderdale, FL, May, 2008 (Colwell, Esposito) 1 paper at the COSPAR in Montreal, July 2008 (Colwell) 2 paper at The Science of Solar System Ices workshop in Oxnard, CA, May 2008 (Hendrix) 6 papers at Saturn After Cassini/Huygens workshop in London, July 2008 (Hendrix, Ohtsuki, Albers, Sremcevic, Esposito, Colwell) Public Outreach and Press Activities (May - Jul 2008) 1: public talk - Esposito, Ball Aerospace, “History of Saturn’s Rings“, June 27 0: press releases 0: press conferences

Backup Material

UVIS: Publications - 2008 Ajello, J. M., M. H. Stevens, A. I. F. Stewart, K. Larsen, L. W. Esposito, J.E. Colwell, W. E. McClintock, G. Holsclaw, J. Gustin, W. R. Pryor. 2007. Titan Airglow Spectra from Cassini UVIS: I. EUV Analysis. Geophys. Res. Lett. 34, L24204, doi:10.1029/2007GL031555. (Published December 25, 2007) Ajello, J, J. Gustin, A.I.F. Stewart, K. Larsen, L.W. Esposito, W. Pryor, W. McClintock, M. H. Stevens, C.P. Malone and D. Dziczek. 2008. Titan airglow spectra from the Cassini Ultraviolet Imaging Spectrograph: FUV disk analysis. Geophys. Res. Lett. 35, L06102, doi:10.1029/2007GL032315. (Published 3/21/08) Brilliantov, N., N. Albers, F. Spahn, and T. Poeschel. 2007 "Collision dynamics of granular particles with adhesion" Physical Review E. 76, 051302-1. LASP Reprint #1098. (Published Nov. 7, 2007) Esposito, L.W., B. K. Meinke, J.E. Colwell, P.D. Nicholson, M.M. Hedman. 2008. Moonlets and Clumps in Saturn’s F Ring. Icarus (Published March 2008) Hendrix, A.R., C.J. Hansen. 2008. Ultraviolet Observations of Phoebe from Cassini UVIS. Icarus. (Published Feb. 7, 2008) Hendrix, A.R., Hansen, C.J.. 2008 The Albedo Dichotomy of Iapetus Measured at UV wavelengths. Icarus. (Published Feb. 7, 2008) Jones, G. H., E. Roussos, N. Krupp, U. Beckmann, A. J. Coates, F. Crary, I. Dandouras, V. Kikarev, M. K. Dougerty, P. Garnier, C. J. Hansen, A. R. Hendrix, G. B. Hospodarsky, R. E. Johnson, S. Kempf, K. K. Khurana, S. M. Krimigis, H. Krueger, W. S. Kurth, A. Lagg, H. J. McAndrews, D. G. Mitchell, C. Paranicas, F. Postberg, C. T. Russell, J. Saur, M. Seiss, F. Spahn, R. Srama, D. F. Strobel, R. Tokar, J.-E. Wahlund, R. J. Wilson, J. Woch, D. Young. 2008. The Dust Halo of Saturn’s Largest Icy Moon, Rhea. Science. (2008) (published March 7, 2008) Liu, X., D.E. Shemansky, C.P. Malone, P.V. Johnson, J.M. Ajello, I. Kanik, A.N. Heays, B.R. Lewis, S.T. Gibson and G. Stark. 2008. Experimental and coupled-channels investigation of the radiative properties of the N2 1Σ–X 1Σ band system. JGR. (Published Feb. 2008)

UVIS: Publications (In Press) Aguilar, A., J.M, Ajello, R.S. Mangina, G.K. James, H. Abgrall, E. Roueff. 2008. The Electron Excited Middle UV to Near IR Spectrum of H2: Cross sections and Transition Probabilities. ApJ. Supp. (Submitted March 2007, accepted February 2008, will be published in July 2008) Ajello J.M., A. Aguilar, R. S. Mangina, G. K. James, P.Geissler, L. Trafton. 2008. The Middle UV to Near IR Spectrum of Electron Excited SO2. JGR-Planets. (Submitted March, 2007, accepted Feb. 2008, in press for March or April)

UVIS: Publications (Submitted) Andre, N., M. Blanc, S. Maurice, P. Schippers, E. Pallier, T. I. Gombosi, K. C. Hansen, D. T. Young, F. J. Crary, S. Bolton, E. C. Sittler, H. T. Smith, R. E. Johnson, R. A Baragiola, A. J. Coates, A. M. Rymer, M. K. Dougherty, N. Achilleos, C. S. Arridge, S. M. Krimigis, D. G. Mitchell, N. Krupp, D. C. Hamilton, I. Dandouras, D. A. Gurnett, W. S. Kurth, P. Louarn, R. Srama, S. Kempf, J. H. Waite, L. W. Esposito, J. T. Clarke. (2008) Magnetospheric Regions and Associated Plasma Processes: Synopsis of Cassini Observations During Orbit Insertion. Rev. Geophys. (Submitted July 2007.) Parkinson, C. D., A. C. Barr, M. C. Liang and Y. L. Yung. 2008. “Habitability of Enceladus: Planetary Conditions for Life”. Origin of Life and Evolution of Biospheres. (Submitted 8/15/07) Pryor, W., P. Gangopadhyay, B. Sandel, T. Forrester, E. Quemerais, E. Moebius, L. Esposito, I. Stewart, B. McClintock, A. Jouchoux, J. Colwell, V. Izmodenov, Y. Malama, K. Tobiska, D. Shemansky, J. Ajello, C.Hansen, M. Bzowski and P. Frisch. 2008. Radiation transport of heliospheric Lyman-alpha from combined Cassini and Voyager data sets. Astronomy and Astrophysics. (Submitted October 16, 2007) Howard, J.E. 2008. "Stability of Hamiltonian Flows" Scholarpedia. (Submitted in October.) No printed copy, just online.

UVIS: Science Presentations - 2008 EGU, Vienna, 13-18 April 2008 Albers: "Saturn's F Ring: Simulations and Observations by Cassini UVIS” Poster Esposito: “ History of Saturn’s Rings “ LPSC, March 2008, Houston, Texas C. Hansen, L. Esposito, J. Colwell, A. Hendrix, B. Meinke, I. Stewart: New Occultation Observation of Enceladus’ Plume A.Hendrix and C. Hansen: Iapetus: New Results from Cassini UVIS Second Titan Workshop, Miami, March 24-26, FL, USA Yung: with Liang, M. C., Henze, D., Gurwell, M. A. Laboratoryhydrocarbonkinetics, isotopic fractionation, and the evolution of Titan’s atmosphere. Astrobiology Science Conference April 14 - 17 2008, Santa Clara Convention Center, CA Yung: with Parkinson, C. D., M.-C. Liang, J. L. Kirschvink.Habitability at Enceladus: Planetary Conditions for Life

UVIS: Outreach - 2008 #: Press releases Esposito: “Cassini Tastes Organic Material at Saturn's Geyser Moon“, Related to March 26 Press Conf. at NASA #: Press conferences & interviews Esposito: “New Details From Close Flyby of Saturn Moon Enceladus“, News Briefing at NASA Headquarters, March 26, 2008 #: EPO: Talks to school children, teachers and public Colwell: "Running Rings Around Saturn" Talk to about 30 students at Stetson University, February 19 Esposito: “History of Saturn’s Rings“ 1 at LASP Feb. 4, and three at JPL, March 17, 18 & 19, both public and technical) Esposito: “History of Saturn’s Rings“, Earth & Space Sciences Seminar Series, Von Karman Auditorium, JPL March 17-19 Esposito: “History of Saturn’s Rings“ public lecture at University of New Mexico, April 4 Larsen: “Cassini results in Saturn Orbit“ at Starfest in Denver, April 18 Hendrix: “Enceladus: The Newest Wrinkle from Cassini’s Tiger-Striped Moon“, Von Karman Lecture Series, Pasadena, CA, March 20-21.