From spencer Mon Sep 11 10:51:14 1995 From spencer Mon Sep 11 10:51:14 1995 To: oleroemer Subject: Ole Roemer Messenger X-Sun-Charset: US-ASCII Content-Length: 12064 X-Lines: 275 Status: RO __________________________________________________________________________ T H E O L E R O E M E R M E S S E N G E R _______________________________________________ JJJJ C G JJJJJJ I E JJJJ __________________________________________________________________________ Newsletter of the International Jupiter Watch Satellite Discipline Issue 18 September 11, 1995 Editor and Discipline Leader: John Spencer Voice: (520) 774-3358 Lowell Observatory Fax: (520) 774-6296 1400 W. Mars Hill Rd. (Note the new telephone area code) Flagstaff, AZ 86001 Internet: spencer@lowell.edu FTP site: ftp.lowell.edu, directory pub/ijw E-mail exploder address: oleroemer@lowell.edu ___________________________________________________________________________ CONTENTS 1) Io Activity Update 2) Use of "Exploder" capability 3) IRTF Io daily monitoring 4) Dust from Io? 5) HST Cycle 5 imaging of Io 6) Io workshop at DPS 7) IJW Satellites sesson at DPS 8) Jupiter in 1996 9) Proposal deadlines 10) Galileo update 11) IUE Auroral monitoring campaign in 1996/1997 12) Publications in the pipeline ___________________________________________________________________________ 1) IO ACTIVITY UPDATE To summarize recent "Io Volcano News" messages, another new eruption appeared on Io around July 20th, probably at the unnamed caldera at 351 W, 22 N, and is still continuing though it has faded since late July. Yet another eruption of similar intensity appeared near 12 W, 28 N, in mid-August and is also still visible, though it appears to be fading faster than the July event. Loki also brightened in late August, and is probably still bright. Jane Spencer and I observed the Io Jupiter occultation reappearance last night (September 11 UT), and though the data are not yet analysed, Io looked quite faint. ___________________________________________________________________________ 2) USE OF "EXPLODER" CAPABILITY We recently discovered that the Ole Roemer mailing list can be used as an exploder (by mailing to oleroemer@lowell.edu). Please use this capability sparingly, and restrict discussions that only involve a few people to those people only. If the exploder proves too useful to restrict in this way, but generates more mail than casual subscribers can tolerate, we may want to set up two mailing lists, one for the exploder and one for "moderated" messages, but in the interest of simplicity I'd rather avoid the dual mailing list if possible. Let me know if you have opinions on this subject ___________________________________________________________________________ 3) IRTF IO DAILY MONITORING The "Daily Monitoring" program of Io (and Jupiter) observations at the IRTF is starting to get going. The program will execute a standard series of NSFCAM observations of Io and Jupiter every evening this fall when NSFCAM is on the telescope (i.e., about half the time), weather permitting, for as long as Jupiter is far enough away from the sun to be observable. If the program is deemed a success, we hope it will be continued through the duration of the Galileo mission. The Io observations, which are all at a plate scale of 0.056 arcsec/pixel, consist of two "plain" L' (3.8 micron) Io/sky pairs, followed by two sets of real-time "Shift and Add" images with different bin positions, then five M (4.8 micron) Io/Sky pairs, which have low S/N but will be useful if we see a large outburst. There is also a series of similar exposures of a local standard, BS6051, for photometric and PSF calibration. The images from each night will be archived as compressed tar files (with Io and Jupiter images in separate archives for each night along with their respective stellar calibrations), and will be available to anyone who wants them from irtf.ifa.hawaii.edu, directory pub/galileo. The sequence isn't yet finalised, but test sequences have already produced some great images so we are confident that the program will be a success. ___________________________________________________________________________ 4) DUST FROM IO? You will have received this message through the "Exploder", but it's interesting enough to be worth repeating here... Date: Fri, 08 Sep 1995 13:17:34 -0600 (MDT) From: Mihaly Horanyi Dear Io fans, Galileo recently plowed through intense dust 'storms'. The dust impact rate jumped from a few to 20,000 (?) a day. Some time ago I worked on models how dust particles from within the Jovian magnetosphere (from Io!, for example) could get energized and ejected from the system. I read these `Io Volcano News' with great hope to find the connection between volcanic activity on Io and the dust streams detected by Ulysses and Galileo. Could any one of you help to graph a time line for Io's recent activity? If it is all true, tiny (0.01? micron) dust particles should get out very fast with velocities in excess of 100 km/s, so it should be possible to find the connection between Io activity and the dust streams. Regards, Mihaly Horanyi ___________________________________________________________________________ 5) HST CYCLE 5 IMAGING OF IO In July 1995 a team consisting of John Spencer, Melissa McGrath, Alfred McEwen, Doug Nash, Paola Sartoretti, John Clarke, Gilda Ballester, and John Trauger obtained images of all longitudes of Io in eleven filters between 2550 A and 7900 A. We found two suprises: the possible detection of the Pele plume off Io's limb at 2550 A, and the appearance of a large bright spot near 330 W, 10 S, where only a small, less-bright spot is visible in March 1994 and Voyager images. More details at DPS... ___________________________________________________________________________ 6) IO WORKSHOP AT DPS This from Ashley Davies... By now you should have received the program for the workshop. The workshop will be held in the Director's Room (lower level: ie, closer to the mantle) of the Ritz-Carlton Hotel, Mauna Lani, Hawaii, 8 October 1995. We look forward to seeing you! Ashley Davies (for the Committee). tel: (818) 393-1775 e-mail: agd@kookaburra.jpl.nasa.gov Io Workshop WWW page: http://galileo.ifa.hawaii.edu/dps95/io.html ___________________________________________________________________________ 7) IJW SATELLITES SESSION AT DPS We will hold our annual meeting of the IJW satellites discpline on Friday lunchtime at DPS, (Noon-1:30pm, Friday 13th October) in the Director's Room. Let me know if you have anything you'd like to discuss there. ___________________________________________________________________________ 8) JUPITER IN 1996 Next Jupiter opposition is on July 4 1996. 1996 Galileo perijove passes, which will allow medium-resolution Io observations and high-resolution observations of the named satellites, occur as follows: G1: July 5 1996 (Ganymede targeted) G2: Sept. 7 1996 (Ganymede targeted) C3: Nov. 6 1996 (Callisto targeted, Europa untargeted) ___________________________________________________________________________ 9) PROPOSAL DEADLINES HST Cycle 6 proposals (July 1 1996 - June 31 1997) are due on September 15th. The next servicing mission, which will replace the FOS and GHRS spectrographs with the NICMOS near-IR camera and STIS imaging spectrograph, will occur during this cycle, in February 1997, and all spectroscopic observations in Cycle 6 must be completed by the servicing mission. Jupiter will be far enough from the sun to be observable with HST (>50 degrees) between Feb. 20 1996 and Nov. 16 1996, and again between March 26 1997 and December 21st 1997. IRTF proposals for February 1996 - July 1996 are due on October 2nd. ___________________________________________________________________________ 10) GALILEO UPDATE The Galileo probe release and deflection maneuver in July were successful, and the spacecraft is on target for the Europa flyby/Io encounter/probe entry/Jupiter orbit insertion on December 7th. There is a problem with a check valve in the helium pressurization system, which has stuck in the open position, but the project says this isn't likely to cause serious problems. More information on the current status of the spacecraft and the mission is obtainable from http://www.jpl.nasa.gov:80/galileo/ A long document from Alfred McEwen, detailing Galileo imaging plans for Io is available from the ftp site (ftp.lowell.edu, directory pub/ijw). It's called GalileoIoSSI.doc ___________________________________________________________________________ 11) IUE AURORAL MONITORING CAMPAIGN IN 1996/1997 IUE will be devoting 512 hours of observing time to monitoring the Jovian aurorae in August-September 1996, and 320 hours in 1996. Io and the Io torus will also be observed. It may be worth planning intensive simultaneous monitoring of the Io volcanos, to look for correlations: contact Tim Livengood (livengood@gsfc.nasa.gov) or Renee Prange (prange@ias.fr) for more details. ___________________________________________________________________________ 12) PUBLICATIONS IN THE PIPELINE Here's a list of recent Io publications and preprints: let me know if you have others to add to the list. Howell RR. 1995. Thermal emission from lava flows on Io. Icarus (submitted) Howell RR, Klassen DR. 1995. Volcanic activity on Io during 1987-1992: 4.8 micron photometry. Icarus (submitted) Johnson TV, Matson DL, Blaney DL, Veeder GJ, Davies AG. 1995. Stealth plumes on Io. Geophys. Res. Lett. submitted Khanna RK, Pearl JC, Dahmani R. 1995. Infrared spectra of solid phases of sulfur trioxide : Possible identification of solid SO$_3$ on Io's surface. Icarus 115: 250-57 DL Matson, TV Johnson, DL Blaney, GJ Veeder, 1995. Ground-based observations of Io. Reviews of Geophysics 33 Suppl. 505-508 McEwen AS. 1995. SO$_2$ rich equatorial basins and epeirogeny of Io. Icarus, in press T Nakamura, M Yoshikawa, 1995. Close encounters and collisions of short-period comets with Jupiter and its satellites. Icarus 116, 113-130 Nash DB, Betts BH. 1995a. Laboratory infrared spectra (2.3--23 microns) of SO$_2$ phases: Applications to Io surface analysis. Icarus In press Nash DB, Betts BH. 1995b. Ices on Io: Composition and texture. Submitted to Solar System Ices ed. Schmitt B, de Bergh C, Festou M. Kluwer Academic Schenk, P. 1995. The mountains of Io. Astronomy 23, 1: 46-51 Schenk, P. 1995. 3-D Moons: Hyperstereo of the outer solar system, Stereo World, 22, 1, 14-19. (Copies can be obtained by writing Stereo World PO Box 398, Sycamore, OH 44882). Spencer, J.R, and N. M. Schneider, 1995. Io on the eve of the Galileo mission. Ann. Rev. Earth. Planet. Sci., Submitted. Summers ME, Strobel DF. 1995. Photochemistry and vertical transport in Io's atmosphere and ionosphere. Icarus (submitted) Trafton LM, Caldwell JJ, Barnet C, Cunningham CC. 1995b. The gaseous sulfur dioxide abundance over Io's leading and trailing hemispheres: HST spectra of Io's C$^1$B$_2$ - X$^1$A$_1$ band of SO$_2$ near 2100 \AA. Astrophys. J. (in press) Trafton LM, Matson DL, Stansberry JA. 1995a. Surface/atmosphere interaction and volatile transport (Triton, Pluto, and Io). Submitted to Solar System Ices ed. Schmitt B, de Bergh C, Festou M. Kluwer Academic Wienbruch U, Spohn T. 1995. A self sustained magnetic field on Io? Planet. Space Sci. (in press) _____________________________________________________________________________