Dividing night from day on Saturn's rings

In this image by the international Cassini spacecraft, Saturn's shadow is captured creeping across the rings. The bottom half of the image shows the bright rings reflecting sunlight from their icy particles, whereas the top is partially obscured in shadow from the gas giant.

The planet's night side can be seen through gaps in the rings on the right side of the image, where it is dimly lit by light reflected from the rings.

The mosaic of four images was taken in visible light by Cassini's narrow-angle camera on 5 November 2006 when Cassini was 1.5 million kilometres from the ringed giant. At the time, Cassini was still a relatively new tourist at Saturn, and was in the middle of its primary mission, which lasted from 2004 to 2008.

The spacecraft was also spending time in an inclined orbit above Saturn, allowing it to have a bird’s eye view of the rings, as seen here, where the giant planet’s shadow creates a ‘terminator’ line of day and night across the rings.

The primary mission was followed by the Equinox mission (2008–2010) and the Solstice mission (2010–2017). The incredible tour of the Saturn system ended with the Grand Finale when Cassini got closer to the rings than ever before, prior to plunging into the planet's crushing atmosphere on 15 September 2017, at the planned end of the mission.

The Cassini mission is a cooperative project between NASA, ESA, and Italy's ASI space agency. This image was published via NASA in March 2018.