17099( 35) - 09-Aug-2024 18:34:54 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17099 Version: 35 Check-in Time: 09-Aug-2024 18:34:54 STScI Edit Number: 27 Title Ganymede's water atmosphere in eclipse ------------------------------------------------------------------------------------ Type Cycle GO 30 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Lorenz Roth Royal Institute of Technology Y CoI: Dr. Carl Schmidt Boston University N CoI: Dr. Joachim Saur Universitat zu Koeln N CoI: Dr. Pippa Molyneux Southwest Research Institute N CoI: Dr. Kurt David Retherford Southwest Research Institute N CoI: Dr. Nickolay Ivchenko Royal Institute of Technology N ------------------------------------------------------------------------------------ Abstract A recent analysis of HST/STIS images has revealed the presence of water vapor in the atmosphere of Ganymede, the largest moon of Jupiter and in the entire solar system. The derivation of H2O was through emissions from oxygen, using the relative brightness of far-UV multiplets at 1304 A and at 1356 A. The findings constitute the first detection of sublimated H2O in the outer solar system. This atmosphere likely collapses when Ganymede is eclipsed by Jupiter since surface temperature and sublimation flux are expected to decrease considerably. Here we propose follow-up observations to confirm the detection of H2O in the atmosphere and characterize the response of the H2O component to eclipse. For this, we use the succesful STIS FUV spectral imaging mode to monitor and map the diagnostic 1304 A and at 1356 A emissions from before to after a ~3-hour eclipse passage of Ganymede. During another eclipse occasion, we use COS and the G230L mode to measure OH aurora from dissociative excitation of H2O for the first time. This visit provides an independent confirmation of the H2O atmosphere. Ganymede is a primary target of ESA's JUpiter Icy Moon Explorer (JUICE) and NASA's Europa Clipper mission. An improved understanding of the moon's neutral environment delivers important information for optimal science planning and addressing the habitability goals for these milestone missions. ------------------------------------------------------------------------------------ Observations Description ------------------------ In visit 1, we use five orbits of STIS FUV-MAMA G140L long-slit spectral imaging for a complete scan of an eclipse passage of Ganymede. With this mode, the OI 1304 A and OI 1356 A are imaged simultaneously. The orbits should optimally be aligned such that Ganymede is in sunlight during the first and last orbit and as much time as possible in eclipse durng the other three orbits. In visit 2, we use two contiguous orbits using COS in the NUV-MAMA G230L mode centered at 3000 A to measure the OH (A-X) band emission in eclipse. For acquisition, we need to use one of the three other Galilean moon and then sweep to Ganymede (which is eclipsed). After acqusition, we use the remaining time for the science exposures. 17099( 35) - 09-Aug-2024 18:34:54 - [ 2] ------------------------------------------------------------------------------------ 17099( 35) - 09-Aug-2024 18:34:54 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: GANYMEDE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE Ganymede near or in eclipse ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=GANYMEDE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS NOT OCC OF GANYMEDE BY JUPITER FROM EARTH ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 4.6 +/- 0.1 Ephemeris Center: EARTH Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 TARGET NAME: GANYMEDE-ECLIPSE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE Ganymede near or in eclipse ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=GANYMEDE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS NOT OCC OF GANYMEDE-ECLIPSE BY JUPITER FROM EARTH, ECL U FULL OF GANYMEDE BY JUPITER FROM EARTH ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 4.6 +/- 0.1 Ephemeris Center: EARTH Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 17099( 35) - 09-Aug-2024 18:34:54 - [ 4] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 TARGET NAME: IO-ACQ ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE Galiliean Moon other than Europa for acquisition ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS NOT OCC OF IO-ACQ BY JUPITER FROM EARTH, SEP OF IO-ACQ EUROPA FROM EARTH GT 10", SEP OF IO-ACQ GANYMEDE FROM EARTH GT 10", SEP OF IO-ACQ CALLISTO FROM EARTH GT 10" ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 5 +/- 0.5 This target is being used to do the target Acqs Ephemeris Center: EARTH Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 TARGET NAME: EUROPA-ACQ ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE Galiliean Moon other than Europa for acquisition ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=EUROPA ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS NOT OCC OF EUROPA-ACQ BY JUPITER FROM EARTH, SEP OF EUROPA-ACQ IO FROM EARTH GT 10", SEP OF EUROPA-ACQ GANYMEDE FROM EARTH GT 10", SEP OF EUROPA-ACQ CALLISTO FROM EARTH GT 10" ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 5 +/- 0.5 This target is being used to do the target Acqs Ephemeris Center: EARTH Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 17099( 35) - 09-Aug-2024 18:34:54 - [ 5] Visit: 01 (STIS FUV visit) Visit Requirements: BETWEEN 30-OCT-2022:09:38:00 AND 30-OCT-2022:10:38:00 On Hold Comments: Additional Comments: Will execute during Oct 30 eclipse Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE STIS/FUV TIME-TA 6X6 G140L 1425 BUFFER-TIME=750 1 2300 S -MAMA G see below (2030 S) Comments: 6"x6" aperture is being used to enable a blind pointing on Ganymede. ------------------------------------------------------------------------------------------------------------------------------------ 2 GANYMEDE-EC STIS/FUV TIME-TA 6X6 G140L 1425 BUFFER-TIME=750 1 2300 S LIPSE -MAMA G see below (2320 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE 1 STIS/FUV TIME-TA 6X6 G140L 1425 none none none none 1 2030.0 S -MAMA G GANYMEDE-ECLIPSE 2 STIS/FUV TIME-TA 6X6 G140L 1425 none none none none 2 2320 S -MAMA G 17099( 35) - 09-Aug-2024 18:34:54 - [ 6] Visit: 02 (COS NUV visit) Visit Requirements: BETWEEN 05-DEC-2022:05:45:00 AND 05-DEC-2022:06:45:00 On Hold Comments: Additional Comments: Will execute during Dec 5 eclipse Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 IO-ACQ COS/NUV ACQ/SEA BOA MIRRORA SCAN-SIZE=2 1 30 S (30 RCH S) Comments: This acquisition mode/setup was used successfully used in program 16211. ------------------------------------------------------------------------------------------------------------------------------------ 2 GANYMEDE-EC COS/NUV TIME-TA PSA G230L 3000 BUFFER-TIME=1030, FP-POS=1 1 1130 S LIPSE G (1130 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 GANYMEDE-EC COS/NUV TIME-TA PSA G230L 3000 BUFFER-TIME=626, FP-POS=2 1 726 S (726 LIPSE G S) ------------------------------------------------------------------------------------------------------------------------------------ 4 GANYMEDE-EC COS/NUV TIME-TA PSA G230L 3000 BUFFER-TIME=626, FP-POS=3 1 726 S (726 LIPSE G S) ------------------------------------------------------------------------------------------------------------------------------------ 5 GANYMEDE-EC COS/NUV TIME-TA PSA G230L 3000 BUFFER-TIME=625, FP-POS=4 1 725 S (725 LIPSE G S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ IO-ACQ 1 COS/NUV ACQ/SEA BOA MIRRORA none none none none 1 N/A RCH GANYMEDE-ECLIPSE 2 COS/NUV TIME-TA PSA G230L 3000 none none none none 1 N/A G GANYMEDE-ECLIPSE 3 COS/NUV TIME-TA PSA G230L 3000 none none none none 2 N/A G GANYMEDE-ECLIPSE 4 COS/NUV TIME-TA PSA G230L 3000 none none none none 2 N/A G GANYMEDE-ECLIPSE 5 COS/NUV TIME-TA PSA G230L 3000 none none none none 2 N/A G 17099( 35) - 09-Aug-2024 18:34:54 - [ 7] Visit: 03 (STIS FUV visit) Visit Requirements: BETWEEN 13-NOV-2022:18:00:00 AND 13-NOV-2022:19:00:00 On Hold Comments: Additional Comments: Will execute during Nov 13 eclipse Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE STIS/FUV TIME-TA 6X6 G140L 1425 BUFFER-TIME=750 1 2300 S -MAMA G see below (2030 S) Comments: 6"x6" aperture is being used to enable a blind pointing on Ganymede. ------------------------------------------------------------------------------------------------------------------------------------ 2 GANYMEDE-EC STIS/FUV TIME-TA 6X6 G140L 1425 BUFFER-TIME=750 1 2300 S LIPSE -MAMA G see below (2320 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE 1 STIS/FUV TIME-TA 6X6 G140L 1425 none none none none 1 2030.0 S -MAMA G GANYMEDE-ECLIPSE 2 STIS/FUV TIME-TA 6X6 G140L 1425 none none none none 2 2320 S -MAMA G 17099( 35) - 09-Aug-2024 18:34:54 - [ 8] Visit: 04 (STIS FUV visit) Visit Requirements: BETWEEN 13-NOV-2022:21:00:00 AND 13-NOV-2022:22:00:00 On Hold Comments: Additional Comments: Will execute during Nov 13 eclipse Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE STIS/CCD ACQ F28X50LP MIRROR CHECKBOX=21, ACQTYPE=DIFFUSE, 1 0.3 S (0.3 DIFFUSE-CENTER=GEOMETRIC-CENTE S) R ------------------------------------------------------------------------------------------------------------------------------------ 2 GANYMEDE STIS/FUV TIME-TA 52X2 G140L 1425 BUFFER-TIME=750 1 2300 S -MAMA G see below (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A GANYMEDE 2 STIS/FUV TIME-TA 52X2 G140L 1425 none none none none 1 1200.0 S -MAMA G 17099( 35) - 09-Aug-2024 18:34:54 - [ 9] Visit: 51 (STIS FUV visit) Visit Requirements: BETWEEN 03-SEP-2023:14:25:00 AND 03-SEP-2023:15:40:00 On Hold Comments: Additional Comments: HOPR repeat of visit 1 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE STIS/CCD ACQ F28X50LP MIRROR CHECKBOX=35, ACQTYPE=DIFFUSE, 1 0.3 S (0.3 GS ACQ SCENARIO BASE1BR DIFFUSE-CENTER=GEOMETRIC-CENTE S) R ------------------------------------------------------------------------------------------------------------------------------------ 2 GANYMEDE STIS/FUV TIME-TA 52X2D1 G140L 1425 BUFFER-TIME=750 1 1700 S -MAMA G see below (1500 S) Comments: 6"x6" aperture is being used to enable a blind pointing on Ganymede. ------------------------------------------------------------------------------------------------------------------------------------ 3 GANYMEDE STIS/FUV TIME-TA 52X2D1 G140L 1425 BUFFER-TIME=750 1 2000 S -MAMA G see below (2313 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A GANYMEDE 2 STIS/FUV TIME-TA 52X2D1 G140L 1425 none none none none 1 1500.0 S -MAMA G GANYMEDE 3 STIS/FUV TIME-TA 52X2D1 G140L 1425 none none none none 2 2313.0 S -MAMA G 17099( 35) - 09-Aug-2024 18:34:54 - [ 10] Visit: 53 (STIS FUV visit) Visit Requirements: BETWEEN 27-DEC-2023:07:45:00 AND 27-DEC-2023:08:45:00 On Hold Comments: Additional Comments: HOPR repeat of visit 03. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE STIS/FUV TIME-TA 52X2D1 G140L 1425 BUFFER-TIME=750 1 1920 S GS ACQ SCENARIO BASE1BR -MAMA G (1920 S) Comments: 52 x 2 aperture is being used to enable a blind pointing on Ganymede. ------------------------------------------------------------------------------------------------------------------------------------ 2 GANYMEDE STIS/FUV TIME-TA 52X2D1 G140L 1425 BUFFER-TIME=750 1 2300 S GS ACQ SCENARIO BASE1BR -MAMA G (2300 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE 1 STIS/FUV TIME-TA 52X2D1 G140L 1425 none none none none 1 N/A -MAMA G GANYMEDE 2 STIS/FUV TIME-TA 52X2D1 G140L 1425 none none none none 2 N/A -MAMA G 17099( 35) - 09-Aug-2024 18:34:54 - [ 11] Visit: 54 (STIS FUV visit) Visit Requirements: BETWEEN 17-SEP-2024:12:00:00 AND 17-SEP-2024:13:00:00 On Hold Comments: Additional Comments: HOPR repeat of visit 51 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE STIS/FUV TIME-TA 52X2D1 G140L 1425 BUFFER-TIME=750 1 1830 S -MAMA G (1830 S) Comments: 6"x6" aperture is being used to enable a blind pointing on Ganymede. ------------------------------------------------------------------------------------------------------------------------------------ 2 GANYMEDE STIS/FUV TIME-TA 52X2D1 G140L 1425 BUFFER-TIME=750 1 2160 S -MAMA G (2160 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE 1 STIS/FUV TIME-TA 52X2D1 G140L 1425 none none none none 1 N/A -MAMA G GANYMEDE 2 STIS/FUV TIME-TA 52X2D1 G140L 1425 none none none none 2 N/A -MAMA G 17099( 35) - 09-Aug-2024 18:34:54 - [ 12] Summary Form for Proposal 17099 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X2, 52X2D1, 6X6, BOA, F28X50LP, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/NUV, STIS/CCD, STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ, ACQ/SEARCH, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=DIFFUSE, BUFFER-TIME=1030, BUFFER-TIME=625, BUFFER-TIME=626, BUFFER-TIME=750, CHECKBOX=21, CHECKBOX=35, DIFFUSE-CENTER=GEOMETRIC-CENTER, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, SCAN-SIZE=2 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 03-SEP-2023:14:25:00 AND 03-SEP-2023:15:40:00, BETWEEN 05-DEC-2022:05:45:00 AND 05-DEC-2022:06:45:00, BETWEEN 13-NOV-2022:18:00:00 AND 13-NOV-2022:19:00:00, BETWEEN 13-NOV-2022:21:00:00 AND 13-NOV-2022:22:00:00, BETWEEN 17-SEP-2024:12:00:00 AND 17-SEP-2024:13:00:00, BETWEEN 27-DEC-2023:07:45:00 AND 27-DEC-2023:08:45:00, BETWEEN 30-OCT-2022:09:38:00 AND 30-OCT-2022:10:38:00, GS ACQ SCENARIO BASE1BR ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, G230L, MIRROR, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names GANYMEDE, GANYMEDE-ECLIPSE, IO-ACQ ------------------------------------------------------------------------------------------------------------------------------------