Cassini sees objects blasting through Saturn's rings

Posted by Kate Taylor

New images from NASA's Cassini spacecraft show strange, half-mile-sized objects punching through Saturn's outermost ring and leaving glittering trails behind them.

The objects are showing up in the F ring, which has a circumference of 550,000 miles, and are leaving trails which the scientists have dubbed 'mini-jets'. After combing through 20,000 images, the scientists have found 500 examples during the seven years Cassini has been at Saturn.

"Beyond just showing us the strange beauty of the F ring, Cassini's studies of this ring help us understand the activity that occurs when solar systems evolve out of dusty disks that are similar to, but obviously much grander than, the disk we see around Saturn," says Linda Spilker, Cassini project scientist.

Scientists have known for a while that relatively large objects can create channels, ripples and snowballs in the F ring, but didn't know what happened to these snowballs after they were created. It now seems that while some are broken up by collisions or tidal forces, others survive and go on to strike through the F ring on their own.

"I think the F ring is Saturn's weirdest ring, and these latest Cassini results go to show how the F ring is even more dynamic than we ever thought," says Carl Murray, a Cassini imaging team member based at Queen Mary University, London.

"These findings show us that the F ring region is like a bustling zoo of objects from a half-mile in size to moons like Prometheus a hundred miles in size, creating a spectacular show."

The objects appear to collide with the F ring at onlyabout miles per hour. The collisions drag glittering ice particles out of the F ring with them, leaving a trail 20-110 miles long.

"Beyond just showing us the strange beauty of the F ring, Cassini's studies of this ring help us understand the activity that occurs when solar systems evolve out of dusty disks that are similar to, but obviously much grander than, the disk we see around Saturn," says Cassini project scientist Linda Spilker.

"We can't wait to see what else Cassini will show us in Saturn's rings."