Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4790c Report Date: 09-May-96:19:56 Version: ********** Check-in Date: ********** 1.Proposal Title: TITAN'S ATMOSPHERE AND EVOLUTION THRU DISK RESOLVED SPECTROSCOPY ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GO Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone George R Lewycky MERRILL LYNCH (212) 236-3038 PROGRAMMER/ANALYST ------------------------------------------------------------------------------------ 7. Abstract By using disk resolved spectroscopy with HST's HRS, a search for formaldehyde (CH2O) will be performed on Titan. Formaldehyde is known to serve as an oligomer to Hydrogen Cyan- ide resulting ultimately in simple precursors, purines and pyrimidines (e.g., adenine, uracils) necessary for DNA. ------------------------------------------------------------------------------------ 8. Scientific Key Words: ATMOSPHERE, SPECTROSCOPY, EVOLUTION FORMATION ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 1.50 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4790c PI: George R Lewycky Proposal Title: TITAN'S ATMOSPHERE AND EVOLUTION THRU DISK RESOLVED SPECTROSCOPY ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ George R Lewycky MERRILL LYNCH USA ------------------------------------------------------------------------------------ 2. Scientific Justification. With Voyager I's findings over a decade ago of an unique atmosphere on Saturn's moon Titan, I propose disk spectroscopy of Titan's atmosphere using HST's GHRS. Information gathered will help in determining the origin and evolution of Titan's atmosphere. Obser- vations have never been made in the proposed wavelength regime, allowing for the discovery of new chemical constituents, most importantly formaldehyde. ------------------------------------------------------------------------------------ 3. Description of proposed observations. This observation consists of a 1.5 hour exposure using the HRS in the large science aperture with the G270M filter to capture formaldehyde at 3170 Angstroms. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Very fine resolution and specific wavelengths are critical to this proposal in order to distinguish formaldehyde from other compounds. A groundbased observation would not be able to find trace amounts of formaldehyde and other minor species due to distance and inter- ference of Earth's atmosphere. This proposal requires spectroscopy, therefore a groundbased observation could not return the required data. Using Synphot at 2700 A we calculate .135 counts per second per diode. For this reason an exposure upwards of one hour is necessary, although the actual count rate might be optimized at the central wavelength specified in the exposure logsheet. Only one target acquisition will be necessary. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Data reduction and analysis will be done at STScI with the aid of a Science Data Analyst. I will use existing resources, such as STSDAS. ------------------------------------------------------------------------------------ 11. Address Information Name: GEORGE R LEWYCKY Category: PI Institution: Address: 7 DURST DRIVE City: MILLTOWN State: NJ Zip Code: 08850 Country: USA Telephone: 908-846-1216 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4790c [ 3] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: TITAN ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE TITAN ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=SATURN | STD=TITAN | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |V=8.4 | OBSERVE TITAN AT GREATEST SEPERATION | | FROM SATURN. | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4790c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 TITAN HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 25S 1 1 CYCLE 2 /1-4 SEARCH-SIZE=5 ONBOARD ACQ FOR 2 SEQ 1-4 NO GAP Comments: STEP-TIME=1.0S EXPECT APPROX. 2700 C/S ------------------------------------------------------------------------------------------------------------------------------------ 2 TITAN HRS ACQ/ 2.0 MIRROR-N2 1 102S 1 1 ONBOARD ACQ FOR 3 PEAKUP Comments: STEP TIME=1.0S ------------------------------------------------------------------------------------------------------------------------------------ 3 TITAN HRS IMAGE 2.0 MIRROR-N2 NX=16 1 256 S 1 1 NY=16 Comments: STEP TIME=1.0S ------------------------------------------------------------------------------------------------------------------------------------ 4 TITAN HRS ACCUM 2.0 G270M 2935 FP-SPLIT=STD 10 14 M 1 1 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4790c [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP IMAGE ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN SEARCH-SIZE=5 NX NY FP-SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 1.50 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 2 /1-4; ONBOARD ACQ FOR 2; SEQ 1-4 NO GAP; ONBOARD ACQ FOR 3; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G270M ------------------------------------------------------------------------------------------------------------------------------------ Target Names TITAN ------------------------------------------------------------------------------------------------------------------------------------