On Planetary Radio's "Questions and Answers" I answered this question: "I read that Uranus got its tilt when it was hit by another object. What does it mean for a ball of gas to be hit -- wouldn't another object just pass through it?"
So many goodies on the Cassini raw images website lately! I am especially excited when Cassini takes photos through red, green, and blue filters so that it's possible to create views that look roughly like what you'd see with your own eyes.
Last week, planetary astronomers Anne Verbiscer, Michael Skrutskie, and Doug Hamilton published a paper in Nature succinctly titled "Saturn's Largest Ring." In the paper, they announce the discovery, using the Spitzer infrared space telescope, of a gargantuan, previously unseen ring around Saturn, encompassing the orbit of Phoebe.
Unmannedspaceflight.com member Astro0 was fiddling around with an interesting-looking sequence of Cassini images when he discovered their purpose -- they were gathered in order to see if Cassini could catch aurorae flaring into being near Saturn's north pole. Cassini sure did!
What should arrive in my inbox today but a press release from the Cassini RPWS and magnetometer teams saying, in part, "the little moon Enceladus is weighing down giant Saturn's magnetic field so much that the field is rotating slower than the planet."