From: LARRY KLAES (ljk4_at_msn.com)
Date: Thu Oct 25 2007 - 06:31:40 PDT
The population of propellers in Saturn's A Ring
Authors: Matthew S. Tiscareno, Joseph A. Burns, Matthew M. Hedman, Carolyn
C. Porco
(Submitted on 24 Oct 2007)
Abstract: We present an extensive data set of ~150 localized features from
Cassini images of Saturn's Ring A, a third of which are demonstrated to be
persistent by their appearance in multiple images, and half of which are
resolved well enough to reveal a characteristic "propeller" shape. We
interpret these features as the signatures of small moonlets embedded within
the ring, with diameters between 40 and 500 meters. The lack of significant
brightening at high phase angle indicates that they are likely composed
primarily of macroscopic particles, rather than dust. With the exception of
two features found exterior to the Encke Gap, these objects are concentrated
entirely within three narrow (~1000 km) bands in the mid-A Ring that happen
to be free from local disturbances from strong density waves. However, other
nearby regions are similarly free of major disturbances but contain no
propellers. It is unclear whether these bands are due to specific events in
which a parent body or bodies broke up into the current moonlets, or whether
a larger initial moonlet population has been sculpted into bands by other
ring processes.
Comments: 30 pages, 10 figures; Submitted to AJ
Subjects: Astrophysics (astro-ph)
Cite as: arXiv:0710.4547v1 [astro-ph]
Submission history
From: Matthew S. Tiscareno [view email]
[v1] Wed, 24 Oct 2007 17:31:21 GMT (3869kb,D)
http://arxiv.org/abs/0710.4547
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