Something’s lurking in Saturn’s rings.
On Monday, NASA released a new image of the giant planet that shows a break in its thin outer F ring. This icy disruption is most likely the handiwork of an unseen object embedded in the ring.
Researchers call these features jets, and they’re a fairly common sight, says Preston Dyches, a spokesman for NASA’s Jet Propulsion Laboratory in Pasadena, California. NASA’s Cassini spacecraft has seen hundreds of ring jets since it started orbiting Saturn in 2004.
Astronomers think that jets form due to the pull of Saturn’s moon Prometheus. This small, potato-shaped moon acts as a cosmic shepherd, sculpting the F ring as it makes its orbit around Saturn. But the moon’s route isn’t perfectly circular, and its uneven pull can create clumps inside the ring that then shoot out as jets, says Dyches.
In the past, jets have caused the rings to morph into braided, clumped, and rippled structures. The latest image showing a break in the F ring was taken on April 8, and more recent pictures from June 10 reveal that the wound has just about stitched itself back up.
While jets may not be that surprising to scientists, close-up pictures of them are about to become even more precious.
The end of the Cassini mission is right on the horizon: It’s slated to wrap up operations on September 15, 2017. In late 2016, the probe will drift high above Saturn’s north pole before diving toward the atmosphere, sailing between the planet and its innermost rings.
During this stage of the Cassini mission, which scientists have dubbed the “grand finale,” the probe will grab samples of Saturn’s upper atmosphere and send back valuable data before plunging to its doom.