Sister Moons
Cassini offers this lovely comparison between two of Saturn's satellites, Dione and Tethys,
which are similar in size but have very different surfaces.
Extensive systems of bright fractures carve the surface of Dione (1,118 kilometers, or 695 miles
across). The double-pronged feature Carthage Linea points toward the crater Turnus at the nine
o'clock position near the terminator, and Palatine Linea runs toward the moon's bottom limb near
the five o'clock position.
In contrast, the surface of Tethys (1,071 kilometers, or 665 miles across) appears brighter and
more heavily cratered. The large crater Penelope is near the eastern limb. The huge rift zone
Ithaca Chasma, which is 3 to 5 kilometers (2 to 3 miles) deep and extends for about 2,000
kilometers (1,200 miles) from north to south across Tethys, is hidden in shadow just beyond the
terminator. For comparison, the Grand Canyon in Arizona is about 1.5 kilometers (1 mile) deep,
and about 450 kilometers (280 miles) long.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March
7, 2005, at a distance of approximately 1.5 million kilometers (908,000 miles) from Tethys and
1.6 million kilometers (994,000 miles) from Dione. The image scale is 9 kilometers (6 miles) per
pixel on Tethys, and 10 kilometers (6 miles) per pixel on Dione.
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 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 . For
additional images visit the Cassini imaging team homepage http://ciclops.org .
Smooth terrain around the western rim of Ikapati Crater on Ceres is visible in this image from NASA's Dawn spacecraft. The area contains material ejected from Ikapati during its formation.
Dawn LAMO Image 120
This raw, unprocessed image of Saturn's moon Enceladus was taken during Cassini's Nov. 6, 2011, flyby which passed within about 300 miles (500 kilometers) of the moon's surface. This encounter wa...
This mosaic of three images was taken by NASA's Dawn framing camera during the high-altitude mapping orbit over the giant asteroid Vesta. The eastern rim is higher than the western rim, and the ove...
Crater Characteristics on Asteroid Vesta
This schematic graphic illustrates the bombardments that lead to colorful splotches and bands on the surfaces of several icy moons of Saturn. The arrow indicating the orbital motion of the moon is ...
Moons Under Bombardment
Bright, wispy-looking fractures reach across the rugged, icy landscape of Dione. See Highest Resolution View of Dione for a close-up view of Dione's icy canyons. The medium-sized crater Dido, wit...
Beyond the Canyons
SDO collected images of the rarest predictable solar event—the transit of Venus across the face of the Sun in 2012.
Venus Transit Across the Sun (2014)
Dark straw-like patterns dot the bright outer B ring just left of the Huygens Gap in the center of this image from the Cassini spacecraft.
B Ring's Straw-like Clumps
Distant Tethys August 20, 2004 Full-Res: PIA06460 With just a bit of detail visible on its lit hemisphere, Tethys was imaged by Ca...
Distant Tethys
The Cassini spacecraft examines the characteristics of Titan's atmosphere as it peers at Saturn's largest moon using a filter sensitive to visible violet light. This image shows atmospheric bandin...
Atmospheric Aspects
This image taken by the Voyager 2 spacecraft of Saturn's A-ring shows the thin F-ring bracketed by its two shepherding satellites. Because the inner moon revolves around the planet slightly faster ...
Shepherd Satellites
From on high, the Cassini spacecraft spots a group of faint spokes against the striped landscape of the B ring, the dark region in the middle of the rings here. The spokes appear as irregular blotc...
Stars and Stripes ... and Spokes
+ See Viewing Options This animation based on data obtained by NASA's Cassini spacecraft shows how the "explosions" of hot plasma on the night side (orange and white) periodically inflate Saturn's...
Saturn's Hot Plasma Explosions
The image shows change in sea ice and solar absorption in the summer months in the Arctic between 2000 and 2014. Blue shows where sea ice has decreased, and red shows where solar radiation absorpti...
Arctic Heating
Almost the entire disk of Titan is illuminated by the sun in this low-phase image of Saturn's largest moon. With the sun behind the Cassini spacecraft, the camera can clearly see the dark Senkyo re...
A Wafer of Titan
Although the crack-like features seen here on Dione's surface appear wispy and faded, they are in reality a series of geologically fresh fractures!
The Wisps of Dione
On July 11, 2005, the Cassini ultraviolet imaging spectrograph observed the star Bellatrix as it passed behind Enceladus, as seen from the spacecraft. The starlight was observed to dim when it got ...
Enceladus Atmosphere Not Global
A partial view of the deck of NASA's InSight lander, where it stands on the Martian plains Elysium Planitia. The image was received on Dec. 4, 2018 (Sol 8).
Partial View of Insight's Robotic Arm and Deck
Come one, come all! Dressed-up characters and space buffs gathered at San Diego Comic-Con International to wave at Saturn on July 19, 2013. They celebrated a special opportunity for NASA's Cassini ...
Hello Saturn, From Comic-Con
The Cassini spacecraft probes Saturn's atmosphere, peering beneath the hazes that obscure the flowing cloud bands at visible wavelengths. Brighter areas in this view generally represent features hi...
Probing the North
These images from NASA's Dawn spacecraft show the brightness/darkness of asteroid Vesta's surface. These images are located in Vesta's Marcia quadrangle.
Brightness and Topography Images of a Dark Hill
In Saturn's bluish north, day ends for the dreamy white clouds that stretch here into twilight. This natural color scene shows middle latitudes in Saturn's north at excellent resolution, and with ...
Infrared South Pole August 11, 2004 Full-Res: PIA05432 This view of Saturn's south pole shows a prominent dark spot, along with flowi...
Infrared South Pole
+ Annotated version The northern and southern hemispheres of Rhea are seen in these polar stereographic maps, mosaicked from the best-available Cassini and Voyager images. Six Voyager images fill...
Rhea Polar Maps - North - March 2012 - Unnanotated
The water-world Enceladus appears here to sit atop Saturn's rings like a drop of dew upon a leaf. Even though it appears like a tiny drop before the might of the giant Saturn, Enceladus reminds us ...
The Dew Drop of Saturn
+ View Full Res + Original PIA09217, July 2007 This image was obtained by Cassini's radar instrument during a flyby on April 10, 2007. The radar antenna was pointing toward Titan at an altitude...
Titan Radar Swaths (T-28 Flyby, April 10, 2007)