The Dark Side of Saturn
Phil Plait, reporting for Slate:
That is Saturn, as seen by the Cassini spacecraft on Oct. 17, 2012. It’s a mosaic of 60 images (taken in violet, red, and infrared light seen here in false color), methodically stitched together to produce this jaw-dropping view, and you absolutely positively must grab the bigger, higher-resolution version. It's stunning.
Stunning work.