Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.


Ring ripples

Credit: NASA/JPL/Space Science Institute

This mosaic of the inner part of Saturn’s rings shows a variety of structures, including narrow gaps, sharp edges and a few ringlets that can be seen in many high-resolution images of the rings. However, unlike most of those images, this mosaic also shows fine-scale periodic variations in the ring’s brightness that extend across this entire region. This pattern was only visible during a period of time around 2009 when the Sun was illuminating the ring from almost exactly edge-on. This unusual lighting geometry highlights vertical structures in the rings and so the periodic brightness variations seen here by Cassini likely represent a corrugation or 'ripple' extending across the rings.

Detailed studies of these ripples show that they are not static features, but slowly evolve over time. Extrapolating the observed trends in these structures backwards in time reveals that they were probably created in the early 1980s, when something, probably a cometary impact, disturbed a wide swathe of the rings. The rings therefore contain echoes of events that happened decades ago, and so preserve a record of the recent history of the outer Solar System.

Author information



Corresponding author

Correspondence to Matthew M. Hedman.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Hedman, M.M. Ring ripples. Nat Astron 1, 580 (2017).

Download citation


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing