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Proposal Identification No.: R2827 Date Received: 2013-Feb-25 14:37:37 Arecibo Observatory William E. Gordon Telescope Observing Time Request COVER SHEET Section I - General Information Submitted for Mar 1 2013. This proposal has not been submitted before. Proposal Type: General Category: Sub-Category: Observation Category: Time Requested this semester: Hours already used for this project: Additional Hours required to complete project: Minimum Useful Time: Expected Data Storage: Proposal Title: ABSTRACT: Regular Planetary Radar Radar Solar System 14 less than 100 GB 20-m Radar Imaging of Lunar Impact Craters and Hollow Terrain We propose 20-m per pixel resolution, bistatic (Arecibo/GBT) S-band radar imaging of two fresh impact craters with complex ejecta blankets and two areas of enigmatic lunar hollow terrains. Observations of the oblique impact craters Messier and Proclus will be used to map the extent of the impact melt deposits, search for channels, ponds and flow features, and determine how melt emplacement was influenced by topography. Radar images of lunar hollow terrains in two areas will be used to search for possible pyroclastic deposits and to determine whether the near-surface properties of the hollow pits is the same or different than the surrounding terrain. These observations will help to determine whether the presence of volatiles was important to hollows formation. The proposed observations are needed because currently available ground-based radar images have resolutions that are too low to discern important geologic details and because they were not imaged by spacecraft radar. Outreach Abstract: Recent spacecraft data of the Moon have revealed new information and mysteries that were not previously known. In particular, we have found that impacts on the Moon sometimes produce more melted rock that was previously thought, and that over time, ejected rocks and melts become covered in dust and rocks. Scientists have also found many interesting volcanic features, including unusual depressions with steep cliffs called lunar hollows. The Arecibo S-band (12.6 cm wavelength) radar can penetrate into the surface up to about a meter and can be used to measure and map the upper structure of the surface and detect buried rocks and surfaces. We propose to use the Arecibo radar transmitter with the NRAO Green Bank Telescope to image two impact craters and two lunar hollows at high-resolution (20 m) to help determine 1.) how impact craters age on the Moon and 2.) how the lunar hollows were formed. 1 Name Lynn M Carter Bruce A Campbell Institution NASA Goddard Space Flight Center Smithsonian Institution E-mail [email protected] Phone 301-614-6026 Student no [email protected] 202-633-2472 no Additional Authors Catherine Neish ([email protected]) Michael Nolan ([email protected]) Donald Campbell ([email protected]) This work is not part of a thesis. Remote Observing Request X Observer will travel to AO Remote Observing In Absentia (instructions to operator) Section II - Time Request The following times are in UT. For these observations night-time is not needed. Begin – End Days Needed at Interval–Interval This Interval 12:30 – 16:15 1 13:15 – 17:00 1 14:00 – 17:45 1 15:00 – 18:15 1 Time Constraints (Must Be Justified in the Proposal Text) We request bistatic (with GBT) observations with the times and dates shown in Table 1 of the proposal document (Aug. 4-7, 2013). The dates were chosen to provide views of the target regions that are away from the Doppler equator and that have reasonable incidence angles based on the viewing geometry and lunar libration. The times include the one hour of radar setup time. These dates will have to be coordinated with the Green Bank Telescope. 2 Section III - Instruments Needed S-Band radar S-band receiver Atmospheric Observation Instruments: Special Equipment or setup: none Section IV - RFI Considerations Frequency Ranges Planned 2378-2382 MHz Section V - Observing List Target List Moon 3