The Hubble Telescope captured a rare Saturn quadruple moon transit back on February 24, 2009.
In this view, the giant orange moon Titan casts a large shadow onto Saturn’s north polar hood. Below Titan, near the ring plane and to the left is the moon Mimas, casting a much smaller shadow onto Saturn’s equatorial cloud tops. Farther to the left, and off Saturn’s disk, are the bright moon Dione and the fainter moon Enceladus.
These rare moon transits only happen when the tilt of Saturn’s ring plane is nearly “edge on” as seen from Earth. Saturn’s rings will be perfectly edge on to our line of sight August 10 and September 4, 2009. Unfortunately, Saturn will be too close to the Sun to be seen by viewers on Earth at that time. This “ring plane crossing” occurs every 14-15 years. In 1995-96, Hubble witnessed the ring plane crossing event, as well as many moon transits and even helped discover several new moons of Saturn.