[X] My Assistant

[jmknapp]

Interesting science plan item today (Jan. 17):

CIRS_020EN_FP3MAP001_PRIME

If I read it right, Enceladus, specifically the south polar region, occulted Tethys at 3:23UTC this morning:

BEGIN_TIME: 190729625.184386 (2006 JAN 17 00:26:00 UTC)
END_TIME: 190742465.184390 (2006 JAN 17 04:00:00 UTC)

FP3 disk map of Enceladus. One SI at 01:47 into observation. Length extended to accommodate all ORS instruments. Duration 03:34. Enceladus is above the lighted disk of Saturn for the first 15 or 20 minutes. S/C just below ring plane, EN above, and ring shadow above that. EN passes edge of ring ansa ca. 02:30. Splendid opportunity for wonderful WAC PR image. For CIRS, this will be an excellent opportunity to determine scattered radiation from CIRS primary - i.e., with a semi-infinite IR source surrounding the small (~3 mrad) cold disk of EN as a sharp occulting disk. AD=3.0-3.4, phase=19-24, (-1, 192)-(0, 230); EN south polar region occults TE (AD=1.9) northern hemisphere at 03:24-03:28; perhaps should center FP3 on center of TE from 03:23-03:29 and blink to cover occultation and EN S polar region........

Low-phase though so maybe any plumes would be invisible against Tethys' disk.

[scalbers]

Interpreting this spectacular Enceladus plume and Saturn image is a bit of a head scratcher for me. I attempted to reproduce this in Celestia and I could get the general idea, yet I either had the Enceladus crescent pointing the wrong way, or it was on the wrong side of the rings. Are we looking at the daylight side of Saturn here? We may be looking at the dark side of the rings. Perhaps if I rotate my display this would make sense assuming we are viewing the night side of Saturn (aligning more logically with the Enceladus crescent). I did note that in this case Enceladus was passing behind Saturn.