Tethys, a moon of Saturn, imaged by the Cassini-Huygens Mission. The canyons of Ithaca Chasma can just be made out at the top left of the image.

	本作品由NASA創作，屬於公有領域。根據NASA的版權政策：“NASA的創作除非另有聲明否則不受版權保護。”（參見：Template:PD-USGov/zh，NASA版權政策或JPL圖像使用政策）
	警告: 使用NASA的logo，徽標等受到美國法律14 CFR 1221的限制。 NASA網站還提供大量來自蘇聯/俄羅斯航天機構，以及其他非美國的太空機構的圖像。這些圖像不一定屬於公有領域。 根據哈勃空間望遠鏡的數據制作的素材，如果不是明確聲明由STScI提供，則可能受到版權保護。[1] 參看{{PD-Hubble}}和{{Cc-Hubble}}或{{Spacetelescope.org}}。 SOHO (ESA & NASA)聯合項目的探測器所創作的所有內容受到著作權保護，並且進行非教育性質的商業應用需要授權。[2] 每日一天文圖（APOD）網站的特色圖片可能受到著作權保護。[3]

Link to the external image:

http://photojournal.jpl.nasa.gov/catalog/PIA06140

Original caption released with the image:

Having passed closer to Tethys than the Voyager 2 spacecraft, Cassini has returned the best-ever natural color view of this icy Saturnian moon.

As seen here, the battered surface of Tethys (1,060 kilometers, or 659 miles across) has a neutral hue. The image here is a mosaic of two footprints. Three images taken in the red, green and blue filters were taken to form a natural color composite. The result reveals a world nearly saturated with craters - many small craters lie on top of older, larger ones, suggesting an ancient surface. At the top and along the boundary between day and night, the moon's terrain has a grooved appearance.

This moon is known to have a density very close to that of water, indicating it is likely composed mainly of water ice. Its frozen mysteries await Cassini's planned close flyby in September 2005.

The view shows primarily the trailing hemisphere of Tethys, which is the side opposite the moon's direction of motion in its orbit. The image has been rotated so that north on Tethys is up.

The images comprising this color view were taken with the Cassini spacecraft narrow angle camera on Oct. 28, 2004, at a distance of about 256,000 kilometers (159,000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 50 degrees. The image scale is 1.5 kilometers (0.9 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 Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org .

Image Credit: NASA/JPL/Space Science Institute