Cassini arrived at Saturn just past the southern summer solstice; by 2009, it had witnessed the equinox. These three views of Saturn were captured by Cassini in March 2006, July 2007, and October 2009, as Cassini orbited in Saturn's ring plane. From that point of view, the massive ring system collapses into a thin line crossing the image.
In 2006, the Sun shone up from the south, illuminating the south pole and casting a huge shadow onto the northern face of the globe; Saturn's northernmost latitudes had a noticeably methane blue color (the same color as Neptune). As the season progressed, the shadows marched southward. As of October 2009, the Sun had crossed Saturn's ring plane, so the ring shadows form a dense black stripe just to the south of the rings. At the same time, the deep methane blue of the northern latitudes has faded. The left two images were made from data archived in the Planetary Data System; the image on the right is composed of raw images. The 2006 image has been mirrored left-to-right in order to make the sense of illumination consistent from picture to picture. The 2006 image includes Enceladus atop the rings; the 2007 one includes Rhea; and the 2009 one includes the shadow of Mimas, perched just above the rings near the terminator.