lundi 22 juin 2015

Triple Crescents

Cassini International logo.

June 22, 2015

A single crescent moon is a familiar sight in Earth's sky, but with Saturn's many moons, you can see three or even more.

The three moons shown here -- Titan (3,200 miles or 5,150 kilometers across), Mimas (246 miles or 396 kilometers across), and Rhea (949 miles or 1,527 kilometers across) -- show marked contrasts. Titan, the largest moon in this image, appears fuzzy because we only see its cloud layers. And because Titan’s atmosphere refracts light around the moon, its crescent “wraps” just a little further around the moon than it would on an airless body. Rhea (upper left) appears rough because its icy surface is heavily cratered. And a close inspection of Mimas (center bottom), though difficult to see at this scale, shows surface irregularities due to its own violent history.

This view looks toward the anti-Saturn hemisphere of Titan. North on Titan is up. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 25, 2015.

The view was obtained at a distance of approximately 1.2 million miles (2.0 million kilometers) from Titan. Image scale at Titan is 75 miles (121 kilometers) per pixel. Mimas was 1.9 million miles (3.1 million kilometers) away with an image scale of 11.4 miles (18.4 kilometers) per pixel. Rhea was 2.2 million miles (3.5 million kilometers) away with an image scale of 13.1 miles (21.1 kilometer) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit or The Cassini imaging team homepage is at and

Images, Text, Credits: NASA/JPL-Caltech/Space Science Institute/Tony Greicius.


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