This magnificent view looks down upon, and partially through, Saturn’s rings from their unlit side. The densest part of the rings occult the bright globe of Saturn. Scientists can use observations like this to precisely determine the concentration of ring particles. When the bright source is the signals coming from the spacecraft, the technique is called a 'radio occultation'. In a radio occultation measurement, a signal is beamed toward Earth from Cassini’s 4-meter (13-foot) wide high gain antenna. Researchers on Earth receive the signal as the spacecraft passes behind the rings. The amount by which Cassini’s radio signal is extinguished tells researchers how densely packed the ring particles are. Scientists can also learn about the size distributions of the particles from occultations. As an added (but tiny) bonus, Atlas (30 kilometers, 19 miles across) is visible as a dark speck against the planet, just outside the A ring. The image was taken in visible red light with the wide angle camera on August 2, 2005, from a distance of approximately 617,000 kilometers (383,000 miles) from Saturn. The image scale is 37 kilometers (23 miles) per pixel.

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