Over at Bad Astronomy, Phil Plait presents a truly stunning view of Saturn throwing a shadow on its rings. It was made by Gordan Ugarkovich, an astronomical image processer (a job I didn’t know existed). The image comprises a mosaic of photos derived from the Cassini spacecraft.
On Oct. 10, 2013, Cassini took 36 shots of Saturn, a dozen each using red, green, and blue filters which approximate true color. Ugarkovic grabbed the raw files, processed them, and assembled them into this mosaic.
The detail is incredible. Cassini was high above Saturn to the north, looking “down” on the ringed world when it took these images. You can see the bizarre hexagonal north polar vortex, the six-sided jet stream flowing around Saturn. The subtle but beautiful bands mark the cloud tops of Saturn’s atmosphere. Unless I’m mistaken, the thin white line you see wrapping around the planet at mid-latitude is the remnant of a vast storm so huge it completely dwarfed our own home world of Earth. And if you look carefully (you can measure it!) you can see that Saturn is highly flattened, its equatorial diameter wider than through the poles.
But dominating this jaw-dropping scene are Saturn’s magnificent rings, seen here far more circular than usual. Cassini’s mission has been to observe Saturn and its moons, which means it tends to stay near the planet’s equator. But now scientists are playing with the orbit more, to do more interesting science. The spacecraft is swinging well out of the equatorial plane, so here we see the rings at a much steeper angle, and they are less affected by perspective.
They jump out in this portrait. . .
There’s more information at Phil’s site, and you can get a huge, high-res copy of this image (4000 X 3200 pixels) here, suitable for use as a screensaver on even a huge screen.