A field of spike-like structures rise up over two miles from the outer edge of Saturn’s B ring in the amazing image above, captured by Cassini during Saturn’s spring equinox in August 2009. These pointy perturbations are caused by the gravitational nudges of tiny (~1/2 mile) embedded moonlets traveling around Saturn within the B ring, causing fine icy particles to “splash” upwards from the otherwise relatively flat ring when they pass by them. The moonlets themselves are held in their orbits by the gravity of Mimas.
The spikes were made visible mainly because of the angle of illumination at the time of equinox, which on Saturn occurs every 15 years and in this instance was on Aug. 11, 2009.
What’s more, the way the moonlets affect Saturn’s B ring is thought to resemble how small clumps of material interacted within the protoplanetary disk that once surrounded our Sun, making Saturn and its rings sort of a miniature model of an infant solar system.
“All in all, we have here a fascinating story of physical mechanisms at work in Saturn’s rings that are at work today, and have been in the past, in other disk systems throughout the cosmos,” said former Cassini imaging team leader Carolyn Porco in Nov. 2010. “In other words, we have uncovered one single physical mechanism that has the power to explain simultaneously a host of seemingly unrelated phenomena…just the kind of discovery we scientists love to make.”
The image above is yet another example of the amazing things that the Cassini mission has taught us about Saturn in its 13+ years in orbit!