CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Ultraviolet Revelation

Ultraviolet Revelation
PIA 09785

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  This low resolution view of Tethys provides scientists with useful information about the moon's surface properties, regardless of the image's small size.

The view, which was taken using an ultraviolet spectral filter, demonstrates that the eastern terrain seen here is less reflective than the west at the short wavelengths of light sampled here. This dramatic difference in brightness is not visible in images taken through other, longer wavelength filters at nearly the same time.

Scientists use images taken at various wavelengths, and at different viewing and lighting angles, to tease out details about the surfaces of Saturn's moons.

This view looks toward the trailing hemisphere on the Saturn-facing side of Tethys (1,062 kilometers, 660 miles across). North is up. Ithaca Chasma is seen here at left.

The image was taken with the Cassini spacecraft narrow-angle camera on Oct. 26, 2007 using a spectral filter sensitive to wavelengths of ultraviolet light centered at 338 nanometers. The view was obtained at a distance of approximately 1.6 million kilometers (972,000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 16 degrees. Image scale is 9 kilometers (6 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, 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 Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission, visit and the Cassini imaging team home page,

Credit: NASA/JPL/Space Science Institute
Released: December 4, 2007 (PIA 09785)
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