On 13 Marsh, 2006, NASA’s Cassini spacecraft took this edge-on view of Saturn’s rings, capturing the moon Mimas above the ring plane, illuminated both by the sun and by “saturnshine,” the tiny moon Janus just above the rings and larger Tethys below. Cassini took the photo from a distance of about 2.7 million kilometres (1.7 million miles), combining red, green and blue spectral filters to produce a natural colour view. Cassini’s mission ended 15 September, 2017, when the spacecraft, virtually out of propellant after its long, successful mission, was directed to plunge into Saturn’s atmosphere.
Scientists are investigating potential causes for the change in colour of the region inside the north-polar hexagon on Saturn, thought to be an effect of the planet’s seasons. In particular, the change to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017.
Skywatchers in the UK looking to the south-southwest at dusk on Monday, 17 September can see the waxing gibbous Moon just 1¾ degrees to the upper left of Saturn, the pair fitting comfortably in the same field of view of binoculars and small telescopes magnifying 25× or less. This is also a good night for spotting Titan, Saturn’s largest and brightest moon.