Bright clumps in the D68 ringlet near the end of the Cassini Mission
Abstract
The D68 ringlet is the innermost narrow feature in Saturn's rings. Prior to 2014, the brightness of this ringlet did not vary much with longitude, but sometime in 2014 or 2015 a series of bright clumps appeared within D68. These clumps were up to four times brighter than the typical ringlet, occurred within a span of ∼ 120° in corotating longitude, and moved at an average rate of 1751.7°/day during the last year of the Cassini mission. The slow evolution and relative motions of these clumps suggest that they are composed of particles with a narrow (sub-kilometer) spread in semi-major axis. The clumps therefore probably consist of fine material released by collisions among larger (up to 20 m wide) objects orbiting close to D68. The event that triggered the formation of these bright clumps is still unclear, but it could have some connection to the material observed when the Cassini spacecraft passed between the planet and the rings.
- Publication:
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Icarus
- Pub Date:
- May 2019
- DOI:
- arXiv:
- arXiv:1901.02043
- Bibcode:
- 2019Icar..323...62H
- Keywords:
-
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 22 Pages, 9 Figures, 3 Supplemental Data Tables, Accepted for Publication in Icarus. Some typographical errors found at proof stage corrected, along with longitude ranges in Table 1