On February 28 2007 the New Horizons (NH) spacecraft will fly by Jupiter on its way to Pluto, and will conduct an extensive series of observations of the Jupiter system, including the Galilean satellites. We propose HST observations to support and complement the New Horizons observations in four ways: 1) Determine the distribution and variability of Io's plumes in the two weeks before NH closest approach, to look for correlations with Io-derived dust streams that may be detected by New Horizons, to understand the origin of the dust streams; 2) Imaging of SO2 and S2 gas absorption in Io's plumes in Jupiter transit, which cannot be done by NH; 3) Color imaging of Io's surface to determine the effects of the plumes and volcanos seen by New Horizons on the surface- New Horizons cannot image the sunlit surface in color due to saturation; 4) Imaging of far-UV auroral emissions from the atmospheres of Io, Europa, and Ganymede in Jupiter eclipse, near-simultaneously with disk-integrated NH UV spectra, to locate the source of the UV emissions seen by NH and use the response of the satellite atmospheres to the eclipse to constrain production mechanisms.

1) To image Io's plumes and surface changes, we will obtain a series of ACS/HRC images of Io in the mid-ultraviolet (for the plume observations) and the visible (for the surface reflectance observations). The high throughput of ACS and the brightness of Io mean that each filter requires a small fraction of one HST orbit for adequate S/N, so we plan to image Io in eight filters, including F220W and F250W for plume imaging at wavelengths where Io?s surface is extremely dark (albedo=0.02 at 250 nm), and six broadband filters from F330W to F850LP to characterize the reflectance spectrum of surface changes (though the mid-UV filters may also be useful for this purpose). Comparison of the plume brightness in F220W and F250W (and for bright enough plumes, F330W) will constrain plume particle sizes. From 2 weeks to 1 week before the New Horizons encounter, before New Horizons has adequate spatial resolution, we will obtain a global inventory of the plumes and surface by imaging Io on five orbits, at five longitudes roughly 72 degrees apart: this will detect all plumes higher than 89 km over Io?s entire surface, and all plumes higher than 33 km over 70% of the surface, to extend the time base of the New Horizons observations. To tie these UV plumes observations to the visible-wavelength plume observations by New Horizons itself, we will repeat two of these longitudes, the ones that put the long-lived large plume Pele and the intermittent large plume Tvashtar on Io?s limb, simultaneously with the New Horizons observations in the period between 5 days and 1 day before encounter. 2) The major sulfur species in the plumes will be detected by imaging Io during Jupiter transit in the F220W (SO2) and F250W (S2) filters. We will also obtain images at longer wavelengths, in the F344N filter (where there are no gas absorptions), and the F435W and F550 M filters, to check for any dust absorption and characterize its wavelength dependence. The same exposure times used in the reflected sunlight sequence (or shorter) will be adequate to obtain a reliable S/N within each exposure, as Jupiter is as bright as Io longward of 310 nm, and much brighter than Io shortward of 310 nm. 4) We will obtain one eclipse ingress visit for each satellite, one orbit each, with a total of 3 HST orbits. The ACS SBC F125LP filter bandpass includes SII 125.6 nm, OI 130.4 n, OI] 135.6 nm, SI 147.9, SI 181.4, and SI] 190.0 nm emissions from Io; and OI 130.4 nm, and OI] 135.6 nm emissions from Europa and Ganymede. A typical integrated FUV brightness from Io in eclipse is ~2 kR, with much brighter features at the limb, sub-Jupiter, and downstream wake. A typical integrated FUV brightness at Europa and Ganymede is ~75 R, with brighter features at the limb and polar ovals, respectively. SOLAR SYSTEM 12 false 0.0 false false false false false false SUPPORTED SOLAR SYSTEM CML range chosen to keep Io acceptably far from Jupiter SATELLITE IO STD=JUPITER STD=IO CML OF IO FROM EARTH BETWEEN 12.0 30.0, SEP OF IO JUPITER FROM EARTH GT 1.0" SOLAR SYSTEM SATELLITE IO STD=JUPITER STD=IO CML OF IO FROM EARTH BETWEEN 80.0 100.0 SOLAR SYSTEM CML range chosen to keep Io acceptably far from Jupiter SATELLITE IO STD=JUPITER STD=IO CML OF IO FROM EARTH BETWEEN 150.0 168.0, SEP OF IO JUPITER FROM EARTH GT 3.0" SOLAR SYSTEM SATELLITE IO STD=JUPITER STD=IO CML OF IO FROM EARTH BETWEEN 224.0 244.0 SOLAR SYSTEM SATELLITE IO STD=JUPITER STD=IO CML OF IO FROM EARTH BETWEEN 296.0 316.0 SOLAR SYSTEM CML range chosen so Pele is transiting Jupiter and close to the limb SATELLITE IO STD=JUPITER STD=IO CML OF IO FROM EARTH BETWEEN 171.4 183.0, SEP OF IO JUPITER FROM EARTH GT -14.0" SOLAR SYSTEM SATELLITE IO STD=JUPITER STD=IO ECL U OF IO BY JUPITER, SEP OF IO JUPITER FROM EARTH GT -13.0" SOLAR SYSTEM SATELLITE EUROPA STD=JUPITER STD=EUROPA ECL U OF EUROPA BY JUPITER, SEP OF EUROPA JUPITER FROM EARTH GT 10.0" SOLAR SYSTEM SATELLITE GANYMEDE STD=JUPITER STD=GANYMEDE ECL U OF GANYMEDE BY JUPITER SOLAR SYSTEM SATELLITE GANYMEDE STD=JUPITER STD=GANYMEDE ACS/HRC Imaging No No F250W ACS/HRC Imaging No No F330W ACS/HRC Imaging No No F550M ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F435W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F892N ACS/HRC Imaging No No F220W ACS/HRC Imaging No No F250W ACS/HRC Imaging No No F330W ACS/HRC Imaging No No F550M ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F435W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F892N ACS/HRC Imaging No No F220W ACS/HRC Imaging No No F250W ACS/HRC Imaging No No F330W ACS/HRC Imaging No No F550M ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F435W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F892N ACS/HRC Imaging No No F220W ACS/HRC Imaging No No F250W ACS/HRC Imaging No No F330W ACS/HRC Imaging No No F550M ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F435W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F892N ACS/HRC Imaging No No F220W ACS/HRC Imaging No No F250W ACS/HRC Imaging No No F330W ACS/HRC Imaging No No F550M ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F435W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F892N ACS/HRC Imaging No No F220W ACS/HRC Imaging No No F220W ACS/HRC Imaging No No F250W ACS/HRC Imaging No No F435W ACS/HRC Imaging No No F344N ACS/HRC Imaging No No F550M ACS/SBC Imaging No No F125LP ACS/SBC Imaging No No F125LP ACS/SBC Imaging No No F125LP Io surface and plumes, longitude 018 (Tic-Visit :proposal-id 10871 :visit-id "01" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 13:12:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 10871 :visit-id "01" :obset-id "A1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0 Io surface and plumes, longitude 090 (Tic-Visit :proposal-id 10871 :visit-id "02" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 12:15:58.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "02" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Io surface and plumes, longitude 162 (Tic-Visit :proposal-id 10871 :visit-id "03" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 12:21:19.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "03" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Io surface and plumes, longitude 234 (Tic-Visit :proposal-id 10871 :visit-id "04" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 12:21:24.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "04" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Io surface and plumes, longitude 306 (Tic-Visit :proposal-id 10871 :visit-id "05" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 12:21:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "05" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Io surface and plumes, longitude 162, repeat visit during the New Horizons observations (Tic-Visit :proposal-id 10871 :visit-id "06" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 12:21:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "06" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Io surface and plumes, longitude 018, repeat visit during the New Horizons observations (Tic-Visit :proposal-id 10871 :visit-id "07" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 12:21:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 358528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "07" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2709 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0 Io plumes in Jupiter transit (Tic-Visit :proposal-id 10871 :visit-id "08" :proposal-version -1 :trans-version "20060322" :date "02-Feb-2007 12:31:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "08" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2769 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 The 4 "Between" time ranges are listed in order of preference (choose one). The crucial constraint is the observing start time relative to the umbral ingress time listed, which is at the exact midpoint of the 2 hour long "between" ranges. Include as many iterations of 300 sec exposures as possible within the time available after umbral ingress (i.e., a series of 5 iterations for a 25 minute period in eclipse is acceptable if the full set of 8 planned here is not available). Of the 4 prioritized "between" time ranges choose the next one down if less than 20 minutes of time after ingress is available within the HST orbit. If none of these times are available then choose an eclipse event before closest approach (i.e., which perhaps would coincide with the NH Observatory Phase ALICE campaign). The exposure sequence should be anchored to match the start of an exposure as close in time as possible to the umbral ingress time provided. Any time in the HST orbit available before the ingress event should also be filled with sub-exposures using the F125LP mode and the same exposure time. Contact CoI Retherford for further clarification. (Tic-Visit :proposal-id 10871 :visit-id "09" :proposal-version -1 :trans-version "20060322" :date "01-Feb-2007 18:07:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 148112 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "09" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2770 :al-overhead-at-end 0 :internal-dur-at-end 200 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence. Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence. Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence. The 3 "Between" time ranges are listed in order of preference (choose one). The crucial constraint is the observing start time relative to the umbral ingress time listed, which is at the exact midpoint of the 2 hour long "between" ranges. Include as many iterations of 600 sec exposures as possible within the time available after umbral ingress (i.e., a series of 3 iterations for a 30 minute period in eclipse is acceptable if the full set of 4 planned here is not available). Of the 3 prioritized "between" time ranges choose the next one down if less than 30 minutes of time after ingress is available within the HST orbit. If none of these times are available then choose an eclipse event before closest approach (i.e., which perhaps would coincide with the NH Observatory Phase ALICE campaign). The 3rd event listed is not viewable with NH owing to occultation by Jupiter, but other sunlit ALICE data at this time will add value. The exposure sequence should be anchored to match the start of an exposure as close in time as possible to the umbral ingress time provided. Any time in the HST orbit available before the ingress event should also be filled with sub-exposures using the F125LP mode and the same exposure time. Contact CoI Retherford for further clarification. (Tic-Visit :proposal-id 10871 :visit-id "10" :proposal-version -1 :trans-version "20060322" :date "01-Feb-2007 18:07:10.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 74064 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "10" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2610 :al-overhead-at-end 0 :internal-dur-at-end 119 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence. The 2 "Between" time ranges are listed in order of preference (choose one). The crucial constraint is the observing start time relative to the umbral ingress time listed, which is at the exact midpoint of the 2 hour long "between" ranges. Include as many iterations of 600 sec exposures as possible within the time available after umbral ingress (i.e., a series of 3 iterations for a 30 minute period in eclipse is acceptable if the full set of 4 planned here is not available). Of the 2 prioritized "between" time ranges choose the next one down if less than 30 minutes of time after ingress is available within the HST orbit. If none of these times are available then choose an eclipse event before closest approach (i.e., which perhaps would coincide with the NH Observatory Phase ALICE campaign). The 1st event listed is preferred because it nearly coincides with a stellar occultation observed by NH ALICE, and provides dayside context to the nightside view for NH during that eclipse event. The exposure sequence should be anchored to match the start of an exposure as close in time as possible to the umbral ingress time provided. Any time in the HST orbit available before the ingress event should also be filled with sub-exposures using the F125LP mode and the same exposure time. Contact CoI Retherford for further clarification. (Tic-Visit :proposal-id 10871 :visit-id "11" :proposal-version -1 :trans-version "20060322" :date "01-Feb-2007 18:07:11.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 74064 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 10871 :visit-id "11" :obset-id "A1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "11" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2686 :al-overhead-at-end 0 :internal-dur-at-end 119 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0 Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence. Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence. Alternate visit to replace visit 11 in case ACS/SBC is not ready in time. This is a place holder only and will need to be updated by the observers if it will actually be exeuted. (Tic-Visit :proposal-id 10871 :visit-id "21" :proposal-version -1 :trans-version "20070108" :date "15-Feb-2007 10:35:10.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 134448 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10871 :visit-id "21" :obset-id "21" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 10871 :visit-id "21" :obset-id "A1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10871 :visit-id "21" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2769 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) true 1 0 Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence. Modify number of iterations not exposure time to fill out an orbit sequence, and truncate the last sub-exposure time to fit the sequence.