Time to open the twenty-eighth door in the advent calendar. Until the New Year, I’ll be opening a door onto a different landscape from somewhere in the solar system. Where in the solar system is this cratered and streaked surface? Click to enlarge >Door 28Resolution is about 280 meters per pixel, and the image covers an area about 280 kilometers square. Credit: NASA / JPL / SSI / color composite by Gordan Ugarkovic It’s Dione, but I’d give ….