From spencer@lowell.edu Wed Mar 1 18:14:09 1995 From spencer@lowell.edu Wed Mar 1 18:14:09 1995 From: spencer@lowell.edu (John R. Spencer) Date: Wed, 1 Mar 95 18:12:19 MST To: oleroemer@lowell.edu Subject: Ole Roemer Messenger Cc: spencer@lowell.edu Status: RO Content-Length: 25263 X-Lines: 506 __________________________________________________________________________ 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 E-mail issue 14 February 28 1995 Editor and Discipline Leader: John Spencer Voice: (602) 774-3358 Lowell Observatory Fax: (602) 774-6296 1400 W. Mars Hill Rd. Internet: spencer@lowell.edu Flagstaff, AZ 86001 ___________________________________________________________________________ EDITORIAL COMMENTS There's extensive information here about upcoming meetings and research proposal deadlines, and about Galileo's plans for Torus observations. Also, the first news of Io volcanic activity for 1995. I'd like to include more information about non-volcanic observing plans for the Galilean satellites in future issues. Please let me know what observations you are planning if you want them to be mentioned. ___________________________________________________________________________ FIRST OBSERVING REPORTS FOR 1995 Report from Bob Howell at WIRO, Wyoming, on Feb. 28th: We did not manage to get the Jupiter occultations/eclipses of Io on the 12th or 21st, but we did manage to get an occulatation reappearance last night (the 28th UT). We observed with our 3.4 um filter, and the occultation reappearance light curve looks very smooth. By eye, I'd say that there are no hotspots which contribute more than about 5% of the total flux. I think I can put more stringent limits on it when I analyze it more quantitatively. We also got a reasonable amount of 5 um photometry over the last week. Once again, I have to be pretty qualitative at this point, because this is our first run of the season and I haven't had a chance to completely tie our local standards to primary ones. However, my impression is that the 5 um flux shows no obvious rotational variation which would indicate a major hotspot. It looks like Io is pretty quite right now. I've actually been encouraged by how well the observations went here. I told you earlier, John, that I didn't expect to get much this year, because with Io so far south it never gets above 2 airmasses for us. Although the high airmass seems to be degrading the seeing enough that I don't expect to get much speckle information, the photometry is coming out reasonable well. We will try to continue most of our standard Io observing program up to solar conjunction and the Galileo encounter. Report from John Spencer at the IRTF, Mauna Kea, on Feb 28th: We observed Io eclipses and occultations by Jupiter at the IRTF on Feb. 17, 19, and 26. Conditions were poor on the 17th, but we got good data on the 19th and 26th and I agree with Bob Howell that volcanic activity is quiet right now. Io's 3 - 5 micron volcanic flux, measured in Jupiter eclipse, was about as low as it ever gets. Direct images and the Jupiter occultation disappearance lightcurve on Feb. 19 suggest several hot spots distributed across the Jupiter-facing hemisphere with similar brightness, probably including Loki (in its "faint state"), something in the southern hemisphere (near Colchis??), and something in the leading hemisphere (near Kanehekili??). Direct imaging and raw photometry of the anti-Jupiter hemisphere on Feb. 27 show no bright hot spots there either. Observations of Io eclipses from Lowell Observatory have so far been thwarted by weather and equipment problems. ________________________________________________________________________________ OBSERVING PLANS FOR 1995: CORRECTION I forgot to mention in the last Messenger that the JPL team (Goguen, Matson, Johnson, Veeder, and Blaney) will be doing direct 5-micron imaging of Io with NSFCAM as well as 5 - 20 micron aperture photometry, so they will be able to obtain direct spatial resolution on Io during their IRTF runs on 6/11-6/13 and 6/16. Also, Jay Goguen's observations on the Palomar 200" are more extensive than stated in the last Messenger. He will be obtaining 4-wavelength global bolometric radiometry of Io on the Palomar 200" on August 5 and 6th, and August 8 to 12, with eclipse reappearances on August 5 and 12 (all dates UT). These will be 1/4 night observations. My apologies for the errors. _______________________________________________________________________________ IO TORUS WORKSHOP A reminder to contact Nick Thomas (thomas@linax1.mpae.gwdg.de) or Nick Schneider (nschneid@NMSU.Edu) for more information about this workshop, to be held in Las Cruces NM, 27-28 April 1995. _______________________________________________________________________________ IO WORKSHOPS AT DPS AND/OR FLAGSTAFF? There are tentative plans for pre-Galileo Io workshops this summer in Flagstaff, and/or at DPS in Hawaii. There may also be a special GRL issue devoted to Galileo Io predictions. More details if and when these plans firm up. _______________________________________________________________________________ SPACE WEATHERING SESSION AT SPRING AGU >From Carle Pieters and Bob Johnson: Below is a description of a session on the weathering of the surfaces of airless bodies: the natural satellites, Mercury, asteroids, Pluto at aphelion, distant comets, interplanetary grains and planetary ring particles. This session will occur as part of the spring AGU meeting in Washington from May 29 to June 2. We would like to encourage you to contribute a paper to this session. The oral part of the session will consist of 13 talks of 15 minutes each, with a 15 minute break, and there will be a poster session in the afternoon. The oral session will be initiated by two 15 minute presentations. The first will be an overview of the remote sensing issues and the second will be an overview of the physical processes occurring. Since these are intended to focus the discussion, we will email an outline of the talks to each person giving a poster or oral presentation about a month before the session. Hopefully the participants can then address related problems. If you have any questions contact either Carle Pieters or Bob Johnson (see below). Note the date for submission of an abstract to AGU is March 9 (see EOS January 10 for submission info). Abstracts are due at AGU headquarters that date; email a copy to us as well. We are not planning specific invited talks, but we can formally invite a few participants if it helps in obtaining travel permission and/or funding. Also, AGU has a one person-one paper rule (except for invited presentations). The invited speakers list is due very soon. P04 Space Weathering: Processes and Products Convenors: R. E. Johnson Thornton Hall B103 Engineering Physics University of Virginia Charlottesville,Va. 22903 Tel: 804-924-7237 Fax: 804-924-1353 rej@virginia.edu C. M. Pieters Geological Sciences Brown University Providence, R.I. 02912 Tel: 401-863-2417 Fax: 401-863-3978 pieters@pds.geo.brown.edu The surfaces of asteroids, most of the natural satellites, interplanetary grains, and planetary ring particles are directly exposed to the vacuum. They are also directly exposed to UV photons, plasma ions, and electrons as well as impacts by micrometeotrites and larger objects. These surface alteration processes can change the spectral and physical characteristics of the object's surface, a process referred to as Space Weathering. This session will be composed of two types of papers: those on laboratory data and theories which describe the physics and chemistry of each of modification processes, and papers describing observations and environmental modelling of specific surfaces, indicating that space weathering is relevant for a particular objects. The session will consist of contributed papers and posters. _______________________________________________________________________________ "SOLAR SYSTEM ICES" SYMPOSIUM This will be held in Toulouse (France) on 27-30 March 1995. Contact myself or Michel Festou (festou@srvdec.obs-mip.fr) for information on the program, or check out the WWW page at http://eggfoo.arc.nasa.gov/ssices.html. There is still time to submit late papers. _______________________________________________________________________________ GALILEO MAGNETOSPHERE WORKING GROUP REQUESTS IO OBSERVATIONS The following message, from Lou Frank, outlines the Galileo UVS plans for observing the Io torus. Though primarily of interest to the Torus Discipline of the IJW, simultaneous groundbased observations of Io's volcanic activity are also requested. GALILEO TOUR OF JUPITER'S MAGNETOSPHERE: ORBIT SEGMENTS CLOSEST TO THE PLANET --Includes the time intervals for the in-situ Fields-and-Particles Measurements (TABLE 1) and the Remote Sensing of the torus with the on-board Ultraviolet Spectrometers (TABLE 2) The following table provides an overview of the intervals during which the fields-and-particles instruments will receive data when the Galileo spacecraft is positioned at radial distances less than 50 Rj. This table should be of particular use for the planning activities of ground- and satellite- based observations at Earth. It is planned that the fields-and-particles instruments will be operated continuously at radial distances inside of 50 Rj for each of the orbits listed below. JOI is Jupiter Orbit Insertion and includes the traversal of Io's torus and the close flyby of this satellite. OWLT is the one-way light time between Earth and Jupiter in units of minutes. The definition of the other parameters should be clear. The time for the orbital parameters is the beginning of the day, 00:00:00. The Magnetospheric Working Group (MWG) for the Galileo Mission is very interested in simultaneous remote observations of Jupiter's aurora, Io's torus, and Io surface activity, especially for the periods listed below when the spacecraft is nearest the planet. For example, only a few spatially-resolved images of the aurora will be obtained with the Near-Infrared Mapping Spectrometer (NIMS) on board the Galileo spacecraft. This is a wonderful opportunity to greatly enhance the value of the Earth-based and the in-situ observations. Further information concerning these Galileo activities can be directed to Scott Bolton (GLLSVC::SBOLTON) or myself (IOWASP::FRANK or frank@iowasp.physics.uiowa.edu). Lou Frank Chair, MWG for the Galileo Mission ~~~~~~~~~~~~~~~~~~~~~~~~~ TABLE 1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C=Callisto, E=Europa, G=Ganymede, according to the close satellite flyby of that orbit. C9 is the exploratory survey into the distant magnetotail. OWLT RANGE ORBIT WEEK DOY DATE (min) (Rj) S-J-S/C E-J-S/C ANGLE ANGLE JOI 1995-49 342 8 Dec 52.0 4.6 107.06 108.66 G1 1996-26 182 30 Jun 34.8 54.3 83.19 84.13 G1 1996-27 183 1 Jul 34.8 46.4 77.82 78.56 G1 1996-27 184 2 Jul 34.8 37.9 70.11 70.63 G1 1996-27 185 3 Jul 34.8 28.7 57.60 57.91 G1 1996-27 186 4 Jul 34.8 18.9 32.32 32.42 G1 1996-27 187 5 Jul 34.8 11.2 35.30 35.40 G1 1996-27 188 6 Jul 34.9 15.5 124.34 124.66 G1 1996-27 189 7 Jul 34.9 24.8 158.05 158.58 G1 1996-28 190 8 Jul 35.0 33.6 173.07 173.77 G1 1996-28 191 9 Jul 35.0 41.4 175.94 175.25 G1 1996-28 192 10 Jul 35.0 48.5 170.27 169.17 G1 1996-28 193 11 Jul 35.1 54.8 165.60 164.27 G2 1996-36 246 2 Sep 38.5 53.3 89.22 79.33 G2 1996-36 247 3 Sep 38.6 46.8 84.12 74.15 G2 1996-36 248 4 Sep 38.7 39.5 77.23 67.17 G2 1996-36 249 5 Sep 38.8 31.5 66.96 56.81 G2 1996-36 250 6 Sep 38.9 22.5 48.84 38.61 G2 1996-36 251 7 Sep 39.0 13.2 5.27 5.73 G2 1996-36 252 8 Sep 39.2 12.2 94.75 105.12 G2 1996-37 253 9 Sep 39.4 21.1 145.71 156.12 G2 1996-37 254 10 Sep 39.6 30.2 165.55 175.70 G2 1996-37 255 11 Sep 39.7 38.4 176.15 172.53 G2 1996-37 256 12 Sep 39.9 45.6 175.71 165.36 G2 1996-37 257 13 Sep 40.0 52.2 170.64 160.03 C3 1996-44 306 1 Nov 45.9 52.9 94.20 84.25 C3 1996-44 307 2 Nov 46.0 46.4 89.09 79.22 C3 1996-44 308 3 Nov 46.1 39.3 82.18 72.38 C3 1996-45 309 4 Nov 46.2 31.2 71.87 62.15 C3 1996-45 310 5 Nov 46.3 22.2 54.25 44.62 C3 1996-45 311 6 Nov 46.4 12.3 10.60 1.46 C3 1996-45 312 7 Nov 46.6 11.2 107.14 116.61 C3 1996-45 313 8 Nov 46.7 21.0 158.28 167.64 C3 1996-45 314 9 Nov 46.9 30.1 176.79 173.74 C3 1996-45 315 10 Nov 47.0 38.0 172.82 163.62 C3 1996-46 316 11 Nov 47.2 44.9 165.96 156.84 C3 1996-46 317 12 Nov 47.3 50.9 160.84 151.82 E4 1996-50 348 13 Dec 49.7 54.8 98.18 92.75 E4 1996-50 349 14 Dec 49.8 49.2 93.87 88.58 E4 1996-50 350 15 Dec 49.8 43.0 88.36 83.20 E4 1996-51 351 16 Dec 49.9 35.8 80.76 75.74 E4 1996-51 352 17 Dec 49.9 27.6 68.91 64.02 E4 1996-51 353 18 Dec 49.9 18.1 45.40 40.66 E4 1996-51 354 19 Dec 50.0 9.4 30.45 35.07 E4 1996-51 355 20 Dec 50.1 15.2 132.02 136.49 E4 1996-51 356 21 Dec 50.2 24.7 162.82 167.13 E4 1996-51 357 22 Dec 50.3 32.8 177.04 178.52 E4 1996-52 358 23 Dec 50.4 39.6 174.01 169.96 E4 1996-52 359 24 Dec 50.5 45.5 167.65 163.73 E4 1996-52 360 25 Dec 50.5 50.6 162.67 158.90 E6 1997-7 046 15 Feb 50.3 50.7 110.39 114.29 E6 1997-7 047 16 Feb 50.2 45.6 105.45 109.49 E6 1997-8 048 17 Feb 50.1 39.8 99.12 103.31 E6 1997-8 049 18 Feb 50.0 32.9 90.33 94.66 E6 1997-8 050 19 Feb 50.0 24.8 76.24 80.71 E6 1997-8 051 20 Feb 49.9 15.3 45.96 50.57 E6 1997-8 052 21 Feb 49.8 9.3 54.93 50.18 E6 1997-8 053 22 Feb 49.8 17.9 132.28 127.40 E6 1997-8 054 23 Feb 49.8 27.5 155.99 150.97 E6 1997-9 055 24 Feb 49.8 35.8 167.86 162.71 E6 1997-9 056 25 Feb 49.8 42.9 175.46 170.17 E6 1997-9 057 26 Feb 49.7 49.2 179.01 175.54 G7 1997-13 089 30 Mar 46.8 51.1 112.42 121.60 G7 1997-14 090 31 Mar 46.7 45.1 107.37 116.64 G7 1997-14 091 1 Apr 46.6 38.2 100.59 109.95 G7 1997-14 092 2 Apr 46.4 30.4 90.50 99.96 G7 1997-14 093 3 Apr 46.3 21.2 72.34 81.89 G7 1997-14 094 4 Apr 46.1 11.4 22.79 32.43 G7 1997-14 095 5 Apr 46.1 12.1 96.32 86.59 G7 1997-14 096 6 Apr 46.0 21.9 140.73 130.93 G7 1997-15 097 7 Apr 45.9 30.6 157.80 147.94 G7 1997-15 098 8 Apr 45.9 38.0 167.59 157.69 G7 1997-15 099 9 Apr 45.8 44.3 174.23 164.37 G7 1997-15 100 10 Apr 45.7 49.8 178.21 169.41 G8 1997-18 123 3 May 42.7 49.7 121.20 132.52 G8 1997-18 124 4 May 42.6 44.2 116.02 127.37 G8 1997-19 125 5 May 42.4 37.8 109.19 120.56 G8 1997-19 126 6 May 42.2 30.4 99.24 110.63 G8 1997-19 127 7 May 42.1 21.6 81.89 93.29 G8 1997-19 128 8 May 41.9 11.8 35.43 46.83 G8 1997-19 129 9 May 41.8 12.0 81.93 70.51 G8 1997-19 130 10 May 41.7 21.9 127.99 116.57 G8 1997-19 131 11 May 41.6 31.2 145.33 133.90 G8 1997-20 132 12 May 41.5 39.2 155.02 143.60 G8 1997-20 133 13 May 41.4 46.2 161.54 150.12 G8 1997-20 134 14 May 41.3 52.5 166.39 154.98 C9 1997-25 173 22 Jun 36.6 52.7 126.23 135.18 C9 1997-26 174 23 Jun 36.4 46.4 121.43 130.25 C9 1997-26 175 24 Jun 36.3 39.4 114.97 123.67 C9 1997-26 176 25 Jun 36.2 31.4 105.40 113.96 C9 1997-26 177 26 Jun 36.0 22.1 87.57 95.99 C9 1997-26 178 27 Jun 35.9 12.8 40.68 48.97 C9 1997-26 179 28 Jun 35.8 12.9 58.64 50.49 C9 1997-26 180 29 Jun 35.7 22.2 105.03 97.03 C9 1997-27 181 30 Jun 35.7 31.5 123.50 115.65 C9 1997-27 182 1 Jul 35.6 39.9 133.74 126.04 C9 1997-27 183 2 Jul 35.6 47.5 140.52 132.98 C9 1997-27 184 3 Jul 35.5 54.4 145.47 138.09 C10 1997-37 257 14 Sep 35.2 50.6 132.70 125.63 C10 1997-38 258 15 Sep 35.3 43.3 126.87 119.63 C10 1997-38 259 16 Sep 35.3 35.3 118.47 111.07 C10 1997-38 260 17 Sep 35.4 26.3 104.62 97.07 C10 1997-38 261 18 Sep 35.4 16.4 77.30 69.60 C10 1997-38 262 19 Sep 35.5 9.2 15.69 23.54 C10 1997-38 263 20 Sep 35.7 17.1 102.26 110.27 C10 1997-38 264 21 Sep 35.8 26.9 127.92 136.07 C10 1997-39 265 22 Sep 35.9 35.5 140.26 148.55 C10 1997-39 266 23 Sep 36.1 42.9 147.98 156.41 C10 1997-39 267 24 Sep 36.2 49.5 153.49 162.06 E11 1997-44 306 2 Nov 40.7 49.6 135.48 124.14 E11 1997-45 307 3 Nov 40.8 43.0 129.98 118.64 E11 1997-45 308 4 Nov 40.9 35.5 122.27 110.92 E11 1997-45 309 5 Nov 41.0 26.9 109.95 98.61 E11 1997-45 310 6 Nov 41.1 17.1 84.36 73.01 E11 1997-45 311 7 Nov 41.2 9.1 2.48 13.67 E11 1997-45 312 8 Nov 41.4 16.2 96.66 107.98 E11 1997-45 313 9 Nov 41.6 26.0 124.47 135.79 E11 1997-46 314 10 Nov 41.7 34.4 137.55 148.86 E11 1997-46 315 11 Nov 41.9 41.8 145.67 156.96 E11 1997-46 316 12 Nov 42.0 48.2 151.46 162.73 E11 1997-46 317 13 Nov 42.2 53.9 155.93 167.18 ~~~~~~~~~~~~~~~~~~~~~~~~~ TABLE 2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NOTE: The following list of times for the remote sensing of the Io torus with the ultraviolet spectrometers (EUV/UVS) on board the Galileo spacecraft was previously published in the e-mail newsletter "INTERNATIONAL JUPITER WATCH, TORUS DISCIPLINE", No. 94-05, 11 November 1994. The day-of-year numbers were correct in the newsletter but the day and month were incorrect. These are corrected in the following list of times. These times vary as the project planning proceeds. Current information concerning the planned EUV/UVS operations can be obtained from Ian Stewart (HADAR::STEWART or stewart@pisces.colorado.edu). ------------------------------------------------------------------ GALILEO UVS/EUV TORUS OBSERVATIONS UVS on from beginning of Midnight Ansa Map thru 14 Rj (torus observing times from end of Noon Ansa Map thru 14 Rj TBD) EUV observing torus from beginning of Midnight Ansa Map thru end of Noon Ansa Map ORBIT J00/G01 midnight ansa map : 25 Jun 96 177/15:25:55 thru 26 Jun 96 178/18:38:52 noon ansa map : 29 Jun 96 181/14: 6:43 thru 30 Jun 96 182/17:47: 2 UVS off at 14 Rj : 04 Jul 96 186/12:54:43 Perijove: 05 Jul 96 187/04:20:38 ORBIT G01/G02 midnight ansa map : 27 Aug 96 240/12:27:21 thru 28 Aug 96 241/17:57: 7 noon ansa map : 31 Aug 96 244/18:54:43 thru 02 Sep 96 246/ 0:50:23 UVS off at 14 Rj : 06 Sep 96 250/21:47:31 Perijove: 07 Sep 96 251/13:37:55 ORBIT G02/C03 midnight ansa map : 27 Oct 96 301/23:55:40 thru 29 Oct 96 303/ 2:51:21 noon ansa map : 31 Oct 96 305/21:15:50 thru 02 Nov 96 307/ 0:38:52 UVS off at 14 Rj : 05 Nov 96 310/19:43:40 Perijove: 06 Nov 96 311/13:29:16 ORBIT C03/E04 midnight ansa map : 11 Dec 96 346/22:26:23 thru 12 Dec 96 347/21:33: 7 noon ansa map : 15 Dec 96 350/ 6:17:16 thru 16 Dec 96 351/ 6:11:31 UVS off at 14 Rj : 18 Dec 96 353/ 9:41:45 Perijove: 19 Dec 96 354/ 3:24:28 ORBIT E06 midnight ansa map : 17 Feb 97 048/ 6: 1:26 thru 17 Feb 97 048/20: 2:23 noon ansa map : 19 Feb 97 050/ 6:10: 4 thru 19 Feb 97 050/21:47:31 UVS off at 14 Rj : 20 Feb 97 051/ 3:17:16 Perijove: 20 Feb 97 051/20:55:40 ORBIT G07 midnight ansa map : 01 Apr 97 091/12:34:33 thru 02 Apr 97 092/ 0:30:14 noon ansa map : 03 Apr 97 093/ 5:38:24 thru 03 Apr 97 093/17:16:47 UVS off at 14 Rj : 03 Apr 97 093/17:16:47 Perijove: 04 Apr 97 094/11: 3:50 ORBIT G08 midnight ansa map : 06 May 97 126/ 3: 8:38 thru 06 May 97 126/13:27:50 noon ansa map : 07 May 97 127/14:38:24 thru 07 May 97 127/18:18:43 UVS off at 14 Rj : 07 May 97 127/18:18:43 Perijove: 08 May 97 128/11:44: 9 ORBIT C09 midnight ansa map : 25 Jun 97 176/ 6:11:31 thru 25 Jun 97 176/15:51:50 noon ansa map : 26 Jun 97 177/14: 6:43 thru 26 Jun 97 177/20:32:38 UVS off at 14 Rj : 26 Jun 97 177/20:32:38 Perijove: 27 Jun 97 178/11:52:48 ORBIT C10 midnight ansa map : 16 Sep 97 259/12:27:21 thru 16 Sep 97 259/22:13:26 noon ansa map : 17 Sep 97 260/23:44: 9 thru 18 Sep 97 261/ 5:42:43 UVS off at 14 Rj : 18 Sep 97 261/ 5:42:43 Perijove: 18 Sep 97 261/23:13:55 ORBIT E11 midnight ansa map : 04 Nov 97 308/12:57:36 thru 04 Nov 97 308/23:32:38 noon ansa map : 06 Nov 97 310/ 1:16:19 thru 06 Nov 97 310/ 7:13:26 UVS off at 14 Rj : 06 Nov 97 310/ 7:13:26 Perijove: 07 Nov 97 311/ 1: 0:28 frank@IowaSP.Physics.UIowa.EDU _______________________________________________________________________________ UPCOMING RESEARCH PROPOSAL DEADLINES 1. The new NRA for FY96 proposals to NASA Planetary Astronomy and Atmospheres should be out by mid-February, with a due date in mid May. 2. The SL9 Data Analysis Program (DAP) announcement was released on Jan 24, with a due date April 24: The NRA can be obtained from this anonymous FTP site: nssdca.gsfc.nasa.gov (128.183.36.23) Log in as "anonymous", with your home computer user ID as the password. The NRA is in the subdirectory "hq-nras", in several different formats. 3. Proposals for the NASA Planetary Geology and Geophysics program are due at LPI on May 22, 1995. Funding is expected to be level. Proposal information, including a file required for submitting proposals, is available electronically as follows. Contact Jeff Plescia (JPLESCIA@SL.MS.OSSA.HQ.NASA.GOV) for more details. The NRA can be obtained from this anonymous FTP site: NSSDCA.GSFC.NASA.GOV (128.183.36.23) (INTERNET) NSSDCA:: (15.188) (DECNET) Log in as "anonymous", with your home computer user ID as the password. The NRA is in the subdirectory "HQ-NRAS.PGG", in several different formats. ________________________________________________________________________________ PUBLICATIONS IN THE PIPELINE P. Sartoretti, M.McGrath, A.McEwen, J.Spencer. 'Post Voyager Brightness Variations on Io' Journal of Geophys. Res. Planets. In press. D. L. Domingue, G. W. Lockwood, D. T. Thompson, Surface textural properties of icy satellites: A comparison between Europa and Rhea. Icarus, in press `The Structure of the Io Torus' by Schneider & Trauger has been accepted by ApJ. Preprints are available by emailing nick@pele.colorado.edu, or by following the instructions for electronic retrieval posted on WWW site whose URL is http://charon.nmsu.edu/~nschneid/pubs.html Note that previous drafts contained a formatting error in Table three - so please use the values in the current preprint. Bob Johnson (rej@uva.pcmail.virginia.edu) has preprints or reprints for the following papers: Formation of Na-Containing Molecular Ions at Io (Icarus 111,65-72,1994); this is a companion paper of the Jody Wilson and Nick Schneider paper you listed. Plasma-Induced Sputtering of an Atmosphere (a review paper) Space Science Reviews 69,215-253,1994. The Effect of Plasma Heating on Sublimation-Driven Flow in Io's Atmosphere, Icarus, in press. _______________________________________________________________________________