Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/2013Fall/CartertagR2827.pdf Дата изменения: Wed Mar 6 01:08:19 2013 Дата индексирования: Fri Feb 28 23:03:10 2014 Кодировка: Поисковые слова: massive stars

Proposal Identification No.:

R2827 Arecibo Observatory

Date Received: 2013-Feb-25 14:37:37 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 pro ject: Additional Hours required to complete pro ject: Minimum Useful Time: Expected Data Storage: Prop osal 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.

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Name Lynn M Carter Bruce A Campbell

Institution NASA Goddard Space Flight Center Smithsonian Institution

E-mail lynn.m.carter@nasa.gov campbellb@si.edu

Phone 301-614-6026 202-633-2472

Student no no

Additional Authors
Catherine Neish (catherine.d.neish@nasa.gov) Michael Nolan (nolan@naic.edu) Donald Campbell (campbell@astro.cornell.edu)

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 I I - Time Request
The following times are in UT. For these observations night-time is not needed.

Begin ­ End Interval­Interval 12:30 ­ 16:15 13:15 ­ 17:00 14:00 ­ 17:45 15:00 ­ 18:15

Days Needed at This Interval 1 1 1 1

Time Constraints (Must Be Justified in the Prop osal 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 I I I - Instruments Needed
S-Band radar S-band receiver

Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none

Section IV - RFI Considerations Frequency Ranges Planned
2378-2382 MHz

Section V - Observing List Target List
Moon

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