Rhea is the second-largest moon of Saturn and the ninth-largest moon in the Solar System. It is the second smallest body in the Solar System for which precise measurements have confirmed a shape consistent with hydrostatic equilibrium, after dwarf planet Ceres. It was discovered in 1672 by Giovanni Domenico Cassini.
The Cassini–Huygens mission, commonly called Cassini, was a collaboration between NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a probe to study the planet Saturn and its system, including its rings and natural satellites. The Flagship-class robotic spacecraft comprised both NASA's Cassini probe, and ESA's Huygens lander which landed on Saturn's largest moon, Titan. Cassini was the fourth space probe to visit Saturn and the first to enter its orbit. The craft were named after astronomers Giovanni Cassini and Christiaan Huygens.
Tethys is a mid-sized moon of Saturn about 1,060 km (660 mi) across. It was discovered by G. D. Cassini in 1684 and is named after the titan Tethys of Greek mythology.
Dione is a moon of Saturn. It was discovered by Italian astronomer Giovanni Domenico Cassini in 1684. It is named after the Titaness Dione of Greek mythology. It is also designated Saturn IV.
Enceladus is the sixth-largest moon of Saturn. It is about 500 kilometers (310 mi) in diameter, about a tenth of that of Saturn's largest moon, Titan. Enceladus is mostly covered by fresh, clean ice, making it one of the most reflective bodies of the Solar System. Consequently, its surface temperature at noon only reaches −198 °C (−324 °F), far colder than a light-absorbing body would be. Despite its small size, Enceladus has a wide range of surface features, ranging from old, heavily cratered regions to young, tectonically deformed terrains.
Mimas, also designated Saturn I, is a moon of Saturn which was discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology.
This article provides a timeline of the Cassini–Huygens mission. Cassini was a collaboration between the United States' NASA, the European Space Agency ("ESA"), and the Italian Space Agency ("ASI") to send a probe to study the Saturnian system, including the planet, its rings, and its natural satellites. The Flagship-class unmanned robotic spacecraft comprised both NASA's Cassini probe, and ESA's Huygens lander which was designed to land on Saturn's largest moon, Titan. Cassini was the fourth space probe to visit Saturn and the first to enter its orbit. The craft were named after astronomers Giovanni Cassini and Christiaan Huygens.
The moons of Saturn are numerous and diverse, ranging from tiny moonlets less than 1 kilometer across to the enormous Titan, which is larger than the planet Mercury. Saturn has 62 moons with confirmed orbits, 53 of which have names and only 13 of which have diameters larger than 50 kilometers, as well as dense rings with complex orbital motions of their own. Seven Saturnian moons are large enough to be ellipsoidal in shape, yet only two of those, Titan and Rhea, are currently in hydrostatic equilibrium. Particularly notable among Saturn's moons are Titan, the second-largest moon in the Solar System, with a nitrogen-rich Earth-like atmosphere and a landscape featuring dry river networks and hydrocarbon lakes found nowhere else in the solar system; and Enceladus since its chemical composition is similar to that of comets. In particular, Enceladus emits jets of gas and dust, which could indicate the presence of liquid water under its south pole region, and may have a global ocean below its surface.
Salih is a small crater near the sub-Saturnian point of Saturn's moon Enceladus. Salih was first discovered in images taken by the Voyager 2 spacecraft. It is located at 6.5° South Latitude, 0° West Longitude and is 4 kilometers across. Available images of this crater have too low resolution to determine anything about the geology of this crater.
Dalilah is a crater in the northern hemisphere of Saturn's moon Enceladus. Dalilah was first discovered in Voyager 2 images but was seen at much higher resolution by Cassini. It is located at 51.89°N 248.54°W and is 16 kilometers across. Fractures have deformed the south-eastern side of Dalilah as well as the dome at the center of the crater. This tectonic deformation was formed through viscous relaxation. Similar deformation is also seen on a slightly larger scale at Dunyazad crater.
Duban is a crater in the northern hemisphere of Saturn's moon Enceladus. Duban was first seen in Voyager 2 images, though the crater has also been seen in much higher resolution Cassini images. It is located at 58.38°N 282.91°W and is 19 kilometers across. In the Cassini image, evidence for significant tectonic deformation can be seen along the northwest rim of the crater.
Shahryar is a crater in the northern hemisphere of Saturn's moon Enceladus. Shahryar was first seen in Voyager 2 images, but was seen at much higher resolution by the Cassini spacecraft. It is located at 58.3° North Latitude, 227.5° West Longitude and is 24 kilometres (15 mi) across. Despite being nearly the same size as the nearby Sindbad crater, Shahryar does not exhibit a dome-like structure on its floor, suggesting it has not undergone significant viscous relaxation. In addition, there is very little evidence that it has experienced tectonic deformation, suggesting that Shahryar is a relatively young crater.
Sindbad is a crater in the northern hemisphere of Saturn's moon Enceladus. Sindbad was first seen in Voyager 2 images, though the southern rim has been seen by Cassini. It is located at 67° North Latitude, 212° West Longitude and is 29.1 kilometers across. A large, dome-like structure occupies the interior of the crater, suggesting the crater has undergone significant viscous relaxation.
Harran Sulci is a region of grooved terrain on the surface of Saturn's moon Enceladus. The feature is centered at 26.7° North Latitude, 237.6° West Longitude and is approximately 276 kilometers long. Harran Sulci bounds Diyar Planitia to the north and east.
The tiger stripes of Enceladus consist of four sub-parallel, linear depressions in the south polar region of the Saturnian moon. First observed on May 20, 2005 by the Cassini spacecraft's Imaging Science Sub-system (ISS) camera, the features are most notable in lower resolution images by their brightness contrast from the surrounding terrain. Higher resolution observations were obtained by Cassini's various instruments during a close flyby of Enceladus on July 14, 2005. These observations revealed the tiger stripes to be low ridges with a central fracture. Observations from the Composite Infrared Spectrometer (CIRS) instrument showed the tiger stripes to have elevated surface temperatures, indicative of present-day cryovolcanism on Enceladus centered on the tiger stripes.
Al-Haddar is an impact crater on Saturn's moon Enceladus, first discovered by the Voyager spacecraft. It is named after Al-Haddar, one of the barber's six brothers in "The Hunchback's Tale" from The Book of One Thousand and One Nights.
Zumurrud is a large impact crater on the anti-Saturn hemisphere of Saturn's moon Enceladus. Zumurrud was first observed in Cassini images during that mission's March 2005 flyby of Enceladus. It is located at 21.9° South Latitude, 181.6° West Longitude, and is 21 kilometers across. Images taken by Cassini during its March and July 2005 flybys of Enceladus revealed a great deal about the geology of this impact crater. Since formation, Zumurrud has been modified by viscous relaxation, tectonic fracturing along the crater's rim, forming canyons hundreds of meters deep, and subsequent cratering, like the small crater along Zumurrud's western rim. In addition, brightness variations can be seen along the eastern crater wall, suggesting variations in water ice grain size.
The exploration of Saturn has been solely performed by crewless probes. Three missions were flybys, which formed an extended foundation of knowledge about the system. The Cassini–Huygens spacecraft, launched in 1997, was in orbit from 2004 to 2017.
