The Cassini team has done it again -- providing stunning images of Saturn during its equinox. The images were released yesterday, the eve of Earth's autumnal equinox.
"Equinox" has been Cassini's broad theme since June 2008, when the craft's primary mission ended. With sunlight hitting the rings edge on, Cassini's cameras have revealed aspects of the rings no one has seen before.
• Scientist have seen evidence for recent (as in days-old) impacts as small objects smack into the rings. The observations provide the first "we actually saw it" confirmation that incoming cosmic crude still eats away at the rings and affects their evolution. In particular, scientist saw streaks of particles up to 3,000 miles long above the rings -- kicked up by one- to two-day-old impacts from objects about 3 feet across and stretched out by their continued orbits around the planet.
• A languid spiral feature discovered in Saturn's D ring is now shown to reach all the way into the planet's B ring, spanning a distance of some 11,000 miles, rather than the 500 miles the feature's initial discovery suggested. The trigger? Again, researchers say an impact is the leading candidate, which hit sometime in the early 1980s. But they say they are puzzled by the spiral's vastness -- another "how did that happen" moment.
• And when it comes to waves in the rings -- surf's up, way up. Initial images of some of these waves along the edges of is known as the Keeler Gap suggested that the trough-to-crest height was about 0.9 miles. But shots taken during the equinox indicate that some of these wave crests actually reach more than two miles above the preceding trough -- roughly twice the height of Arizona's Grand Canyon.
These are among some of the equinox revelations that prompted the mission's imaging-team leader, Carolyn Porco, to describe the equinox scenes as "a moving spectacle" -- in several senses of the word "moving."
The results "have left us with far greater insights into the workings of Saturn's rings than any of us could have imagined. We always knew it would be good," she said in a prepared statement. "Instead, it's been extraordinary."
And congratulations to Dr. Porco. Aside from her stint as science adviser to the latest Star Trek movie (remember the scene at the end where the Enterprise rises ominously from within Titan's methanous smog with Saturn and its rings as a backdrop?), she's just received a fellowship from the Huntington Library in San Marino, Calif. She'll be working on a book about Cassini.