6150( 7) - 12/15/95 10:52 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6150 Version: 7 Check-in Date: ********** 1.Proposal Title: DETECTING THE HYDROXYL RADICAL IN THE JOVIAN MAGNETOSPHERE ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle SOLAR SYSTEM,GIANT PL GO 4 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: SHEMANSKY, DONALD UNIV. OF SOUTHERN CALIFORNIA CoI: Matheson, Philip L. Univ of Southern Cal N CoI: Hu, Hongyao D. Univ of Southern Cal N ------------------------------------------------------------------------------------ 6. Abstract We propose to observe the Jupiter magnetosphere to determine the presence and abundance of the hydroxyl radical(OH). OH has been seen in the region of the icy moons of Saturn by the HST/FOS instrument (GO3644-Cycle 2, August, 1992). The observed abundance implied a source rate 20 times higher than predicted on the basis of ion surface sputtering of H_2O. Plasma content at the orbit of Europa is greater than at Saturn. Sputtering source rates of 3x10^26 mol/s are predicted, or about 1/6 to 1/3 the rate inferred at Saturn's icy satellites. OH may contribute a substantial fraction of OII to the outward moving Io torus plasma. Our physical chemistry model predicts that for a 40% contribution to local plasma density, the Europan sourced OH number density may approach an average of 3 cm^-3. Assuming a path length of 10 R_j, with an OH emission probability of 2.3x10^-5 s^-1 in the OH A-X (0,0) band near 3085 Angstroms the intensity is 5 Rayleighs. This should be observable by the HST/FOS. If the high source rate of OH at Saturn is driven by micrometeoritic gardening of the satellite surfaces, then the same process may be active at Europa, producing a commensurately higher signal. Direct estimates of OH densities along with physical chemistry modeling will provide definitive constraints on possible surface erosion rates of Europa's surface. ------------------------------------------------------------------------------------ Observations Description ------------------------ Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6150( 7) - 12/15/95 10:52 - [ 2] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6150( 7) - 12/15/95 10:52 - [ 3] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: EURTOR ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER, ACQ=1.5 | TYPE = TORUS, LONG = 90, LAT = 0, RAD | = 6.6E+05, POLE_LAT = +90 | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | WND1 = 18-JAN-95 TO 31-JUN-1995 SEP OF | EURTOR EUROPA FROM EARTH GT 10" SEP OF | EURTOR IO FROM EARTH GT 10" SEP OF | EURTOR CALLISTO FROM EARTH GT 10" SEP OF | EURTOR GANYMEDE FROM EARTH GT 10" | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | | ESTIMATED BAND BRIGHTNESS 5 | RAYLEIGHS CONTINUUM IS SKY | BACKGROUND NO SATELLITES IN FIELD OF | VIEW SEP OF LOS EUROPA FROM EARTH GT | 10 SEP OF LOS IO FROM EARTH GT 10 | SEP OF LOS CALLISTO FROM EARTH GT 10 | SEP OF LOS GANYMEDE FROM EARTH GT 10 | ------------------------------------------------------------------------------------------------------------------------------------ 6150( 7) - 12/15/95 10:52 - [ 4] Visit: 01 Visit Requirements: GUID TOL 0.0000556D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 EURTOR FOS/RD ACCUM 4.3 G270H 3090.0 STEP-TIME=0.25, 1 15000S STEP- PATT=SINGLE Comments: SINGLE GUIDE STAR OK BLIND POINTING ACQUISITION. MERGE TO PRODUCE 2 APPROX EQUAL LENGTH ALIGNMENTS PER ORBIT. EXPAND TO FILL 7 ORBITS. ------------------------------------------------------------------------------------------------------------------------------------ 6150( 7) - 12/15/95 10:52 - [ 5] Visit: 02 Visit Requirements: GUID TOL 0.0000556D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 EURTOR FOS/RD ACCUM 4.3 G270H 3090.0 STEP-TIME=0.25, 1 2700S STEP- PATT=SINGLE Comments: SINGLE GUIDE STAR OK BLIND POINTING ACQUISITION. MERGE TO PRODUCE 2 APPROX EQUAL LENGTH ALIGNMENTS PER ORBIT. ------------------------------------------------------------------------------------------------------------------------------------ 6150( 7) - 12/15/95 10:52 - [ 6] Summary Form for Proposal 6150 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters STEP-TIME=0.25 STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM,GIANT PLANETS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GUID TOL 0.0000556D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G270H ------------------------------------------------------------------------------------------------------------------------------------ Target Names EURTOR ------------------------------------------------------------------------------------------------------------------------------------