Mutual Event Sequence (Natural Colors; credits: NASA/JPL/Space Science Institute)

Caption NASA:"Saturn's moon Tethys with its prominent Odysseus Crater silently slips behind Saturn's largest moon Titan and then emerges on the other side.
Tethys is not actually enshrouded in Titan's Atmosphere. Tethys is more than twice as far from Cassini than Titan in this sequence: Tethys is about 2,2 MKM (such as approx. 1,4 MMs) from Cassini, while Titan is about only 1 MKM (approx. 621.000 miles) away.

These two color views were captured about 18 minutes apart, with the view on the right side taking place first.
These images are part of a so-called "Mutual Event Sequence" in which one moon passes close to or in front of another (from CASSINI point of view). Such observations help scientists refine their understanding of the orbits of Saturn's moons.

Images taken using red, green and blue spectral filters were combined to create this Natural Color view. The images were obtained with the Cassini Spacecraft narrow-angle camera on Nov. 26, 2009.
The images were obtained with the Cassini Spacecraft narrow-angle camera on Nov. 26, 2009.
Image scale is roughly 6 Km (a little less than 4 miles) per pixel on Titan and apprx. 13 Km (a little more than 8 miles) per pixel on Tethys".