Giant “snowballs” have been discovered plunging through Saturn’s outermost ring, creating glittering trails of ice dubbed mini-jets, researchers have announced.
The jets were uncovered in new images from NASA’s Cassini orbiter, which has been touring the Saturnian system for the past seven years.
The colliding snowballs are formed as material in Saturn’s F ring coalesces due to the gravitational pull of the nearby moon Prometheus. Scientists estimate that the icy bodies, including the one seen above, are each about 0.62 mile (a kilometer) wide.
Sometimes a snowball sails back through the F ring at a gentle clip of roughly 4 miles (6.4 kilometers) an hour, dragging along icy particles.
The resulting jets “are about 10 kilometers [6.2 miles] wide and extend out from the rings anywhere from 40 to 180 kilometers [25 to 112 miles], depending on their age, with their lengths increasing dramatically over just a few hours,” said Carl Murray, a Cassini imaging team member based at Queen Mary University in London, England.
“At any given time we might expect to see about ten of these if we looked all the way around the F ring.”
Using pictures from Cassini’s narrow-angle camera, scientists were able to track the snowballs at the ends of the mini-jets, such as the one above, as they plowed through Saturn’s F ring.
“We have yet to obtain resolved images of these objects,” Murray said.
“However, when we see an obvious ‘head’ at the end of the mini-jet trail, it tends to have a fuzzy appearance”–suggestive of the halo that surrounds a comet–“produced, perhaps, from material on its surface or F ring core material.”