After a planetary spacecraft is successfully launched on its long journey to its target planetary object, the various teams involved in the mission must checkout the instruments and subsystems they provided. This usually involves taking images to verify that everything is working properly. The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) and the Venus Monitoring…

Cassini flew by Rhea yesterday in an effort to better understand the heavily cratered world with wispy terrain similar to the ice cliffs and fractures of Dione. The image above shows the planned image coverage as Cassini passed only 500 kilometers (310 miles) above Rhea on Saturday. When Cassini was still 76,689 kilometers (47,652 miles)…

The excitement of scientists upon Cassini-Huygens entering the Saturnian System was reserved mostly for Titan, Saturn itself, and its rings. That the other moons might be something more than cratered and dead ice bodies was hardly expected. Enter Iapetus. This strange moon between Phoebe and Titan helped write the exciting new chapter of Saturn moon…

There is a poster-sized image displayed on a board in the public-accessible lobby of the Charles P. Sonnett Space Sciences Building on the University of Arizona campus that correctly portrays Hyperion as one of the reddest objects in our solar system, along side Mars and some of the transneptunion objects. The colors of Hyperion, in…

Titan, the largest of the Saturnian moons, with the thick planet-like atmosphere. The moon with the Earth-like surface, of deeply cut fluid channels, broad sea-like basins, pebbled channel beds, lakes, wind-driven sediments, and occasional craters. The alien moon with water ice as rock carved by periodically flowing methane streams and rivers, with hydrocarbons snowing from…

Rhea might otherwise be the most boring of the Saturnian moons, what with its ancient craters, airless surface, and lack of any recent activity. But therein lies the mystery. Why are there two distinct regions of craters, suggesting an early resurfacing event, and what are the wispy features on the surface that resemble the more…

Somewhere in the raw image above, perhaps the tiny dot in the lower right, may be Polydeuces, a tiny moon discovered by Cassini-Huygens and announced on February 24, 2005 with the following from a mission news report: “Another discovery was a tiny moon, about 5 kilometers (3 miles) across, recently named Polydeuces. Polydeuces is a…

The beautiful wispy terrain on Dione has long tantalized planetary scientists looking over low resolution images of the moon. When Cassini flew by Dione in December 16, 2004 it revealed the wisps to be bright ice cliffs created by the fracturing of the moon’s surface, a result completely unexpected by scientists. This would not be…

Little is known about the tiny moon Helene other than its size (32 kilometers, or 20 miles) and its status as a Trojan moon of Dione (along with Polydeuces). All three moons share an orbit, but Helene lies 60 degrees ahead of Dione and Polydeuces lies 60 degrees behind Dione. More Information Cassini-Huygens Website Saturn’s…

Calypso is a Trojan moon of Tethys orbiting Saturn 60 degrees behind Tethys. Cassini snapped the best image yet of Calypso on September 23, 2005, revealing a colorful and potato-shaped object. More Information Cassini-Huygens Website Saturn’s Moons section Calypso Information Table of Contents Introduction Pan Atlas Prometheus Pandora Janus Epimetheus Mimas Pallene and Methone Enceladus…

Ithaca Chasma is an ancient and gigantic rift cutting across the heavily cratered surface of Tethys. Less surprising than many of the other moons of Saturn, Tethys does have its own mysteries, including bright crater floors, younger plains, and evidence of very early activity that resulted in Ithaca Chasma. More Information Cassini-Huygens Website Saturn’s Moons…

Telesto is a Trojan moon of Tethys orbiting Saturn 60 degrees ahead of Tethys. Cassini took the best ever images of this tiny moon on October 11, 2005. More Information Cassini-Huygens Website Saturn’s Moons section Telesto Information Table of Contents Introduction Pan Atlas Prometheus Pandora Janus Epimetheus Mimas Pallene and Methone Enceladus Telesto Tethys Calypso…

Out of nowhere emerged a Saturn moon to rival Titan in mystery and activity. Here, suddenly, was an ice world not dead but alive and active, spewing out water ice and oxygen from a youthful surface, creating only the second moon atmosphere known in the Saturnian system. Because Enceladus is so small, the atmosphere is…

Two of the newest moons discovered by Cassini, Pallene and Methone are tiny worlds that lie between the orbits of Enceladus and Mimas. The image above may or may not show these two moons, but the camera used by Cassini to snap this image was pointing toward Pallene on September 29, 2005. More Information Cassini-Huygens…

Herschel Crater covers nearly a third of the diameter of Saturn’s small moon Mimas, helping it to resemble the Death Star from Star Wars. Some of the most breathtaking images taken by Cassini of Saturn and its rings have included Mimas in the shot. Crater upon crater upon crater indicate the surface of Mimas is…

The tiny and irregular shaped Epimetheus orbits Saturn with a similar moon called Janus, both of which may have formed when a larger body was broken up during a collision earlier in its history. Because the density of Epimetheus is less than that of water, it may be porous, perhaps just a pile of rubble…

Janus is quite similar to Epimetheus. Both moon share the same orbit and trade places with each other every four years. Janus is heavily cratered and likely very ancient. More Information Cassini-Huygens Website Saturn’s Moons section Janus Information Table of Contents Introduction Pan Atlas Prometheus Pandora Janus Epimetheus Mimas Pallene and Methone Enceladus Telesto Tethys…

The craters on the tiny moon Pandora are muted compared to craters on larger moons because they are filled with collapsed debris. The surface is also covered in fine icy material, perhaps as a result of Pandora’s role as a ring shepherd moon, keeping Saturn’s F ring in line. More Information Cassini-Huygens Website Saturn’s Moons…