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This page describes an image Rhea reappearing after occultation by Titan

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Image caption: On October 27, 2009, NASA’s Cassini spacecraft orbiting around Saturn captured this view of Saturn's moon Rhea as it began to emerge after being hidden by Saturn's largest moon Titan during an occultation. An occultation is a celestial event in which one object moves in front of another and temporarily blocks the first object from view.

In this image, Titan — about 5,150 km across — was closer to the spacecraft at about 1 million km, while Rhea — roughly 1,528 km in diameter — was farther away at about 2.3 million km. Titan’s high-altitude atmospheric haze is visible as a faint glow around its limb, showing the difference in surface and atmospheric properties between these two moons.

Scientists study occultations like this because watching how one moon disappears behind or reappears from another helps refine our understanding of their orbits and physical characteristics.


Image credit: NASA/JPL/Space Science Institute Credit Link

Related glossary terms: Moons , Occultation , Titan

Image license: Public Domain Public Domain icons

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