# Bright clumps in the D68 ringlet near the end of the Cassini Mission

## TL;DR

This paper reports the appearance of bright, moving clumps in Saturn's D68 ringlet around 2014-2015, likely caused by collisions among larger objects releasing fine particles, with implications for understanding ring dynamics.

## Contribution

It provides the first detailed observation and analysis of bright clumps in D68, revealing their properties, motion, and possible origins, enhancing knowledge of ring particle interactions.

## Key findings

- Bright clumps appeared in D68 around 2014-2015.
- Clumps moved at approximately 1751.7 degrees/day.
- Clumps likely composed of fine particles from larger object collisions.

## 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 degrees in corotating longitude, and moved at an average rate of 1751.7 degrees/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 meters 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.