Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/2016Spring/BrozovictagR2954.pdf Дата изменения: Tue Sep 15 04:38:21 2015 Дата индексирования: Mon Apr 11 17:23:54 2016 Кодировка: Поисковые слова: п п п п п п п п п п п п п п п п п п п

Proposal Identification No.:

R2954 Arecibo Observatory

Date Received: 2015-Aug-31 20:21:26 William E. Gordon Telescope Observing Time Request COVER SHEET

Section I - General Information
Submitted for Sep 1 2015. This proposal has been submitted before. The previous proposal number is R2954. Proposal Type: General 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 Solar System 65 37 N/A 3.25 hours 100-500 GB

Arecibo radar ranging measurements of the Galilean satellites in 2016

Our ob jective is to use radar range measurements of the Galilean satellites in order to detect orbital changes due to their tidal interaction with Jupiter. The current search for tides in the jovian system was all done based on the optical astrometry. We used Arecibo in 2015 to demonstrate that radar line-of-sight position measurements can be 50 times more precise than the optical data. These high-accuracy data will provide much more sensitive approach to look for tidal effects. An added benefit to the radar ranging of the Galilean satellites is the reduction in orbital uncertainties for both Jupiter and the satellites. This is our last opportunity to observe the satellites until fall of 2022 because Jupiter will be outside Arecibo's declination window. Outreach Abstract: Our ob jective is to use Arecibo radar to measure very precisely the distance to the Galilean satellites of Jupiter. We will use these measurements to calculate their orbits. We are interested in detecting small orbital changes due to tides. The magnitude of the orbital change can be related to the interior properties of Jupiter and the satellites. This can help us learn about volcanism on Io and about sub-surface ocean on Europa.

Name Marina Brozovic

Michael C Nolan

Institution Jet Propulsion Laboratory, California Institute of Technology University of Arizona

E-mail marina.brozovic@jpl.nasa.gov

Phone 818-354-5197

Student no

michaelcnolan.1@gmail.com

no

1


Additional Authors
L.A.M.Benner, Lance.Benner@jpl.nasa.gov, J.G. McMichael, Joseph.G.Mcmichael@jpl.nasa.gov, P. Taylor, ptaylor@naic.edu, E. Rivera Valentin eriverav@naic.edu, J.E. Richardson,richardson@naic.edu, L.J. Harcke, Leif.J.Harcke@jpl.nasa.gov, R. A. Jacobson, ra j@murphy.jpl.nasa.gov, W.M. Folkner William, william.m.folkner@jpl.nasa.gov, J. D. Giorgini, jdg@tycho.jpl.nasa.gov, M.A. Slade, Martin.A.Slade@jpl.nasa.gov, no students

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 required.

Begin ­ End Interval­Interval ­ ­ ­ ­

Days Needed at This Interval

Time Constraints (Must Be Justified in the Prop osal Text) Please see Table 1 in our proposal. We are requesting 20 tracks, each 3.25 hours long. The S-band transmit is on for 75 min during each track. Our observations are timed so that the Galilean satellites are at their largest separation from Jupiter. We need at least two ranging measurements for each of the satellites: one in East elongation and one in West elongation from Jupiter.

Section I I I - Instruments Needed
2


S-Band radar Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none

Section IV - RFI Considerations Frequency Ranges Planned

Section V - Observing List Target List
Ob ject Date LST window RA, dec hh:mm-hh:mm deg deg Europa Feb 22 10:27-12:26 172, +5 Ganymede Feb 23 10:27-12:26 172, +5 Io Feb 24 10:26-12:26 171, +5 Io Feb 25 10:25-12:26 171, +5 Io Feb 26 10:25-12:26 171, +5 Ganymede Feb 27 10:24-12:25 171, +5 Callisto Feb 28 10:24-12:25 171, +5 Callisto Mar 6 10:18-12:23 170, +6 Europa Mar 7 10:18-12:23 170, +6 Ganymede Mar 8 10:18-12:22 170, +6 Europa Mar 9 10:16-12:22 170, +6 Io Mar 10 10:16-12:22 170, +6 Io Mar 11 10:16-12:21 170, +6 Ganymede Mar 12 10:14-12:21 169, +6 Io Mar 19 10:10-12:19 169, +7 Io Mar 20 10:10-12:19 168, +7 Europa Mar 21 10:09-12:19 168, +7 Callisto Mar 22 10:07-12:17 168, +7 Europa Mar 23 10:07-12:17 168, +7 Io Apr 05 10:01-12:15 167,+7

3