Editing Cassini–Huygens (section)

=== Enceladus flybys ===
[[File:Enceladus PIA06191.jpg|thumb|right|View of Enceladus's [[Europa (moon)|Europa]]-like surface with the [[Labtayt Sulci]] fractures at center and the Ebony (left) and Cufa dorsa at lower left; imaged by ''Cassini'' on February 17, 2005]]
During the first two close flybys of the moon [[Enceladus]] in 2005, ''Cassini'' discovered a deflection in the local magnetic field that is characteristic for the existence of a thin but significant atmosphere. Other measurements obtained at that time point to ionized water vapor as its main constituent. ''Cassini'' also observed water ice geysers erupting from the south pole of Enceladus, which gives more credibility to the idea that Enceladus is supplying the particles of Saturn's E ring. Mission scientists began to suspect that there may be pockets of liquid water near the surface of the moon that fuel the eruptions.<ref name=NASA-20110705/>

On March 12, 2008, ''Cassini'' made a close fly-by of Enceladus, passing within 50&nbsp;km of the moon's surface.<ref name=NASA-20080310/> The spacecraft passed through the plumes extending from its southern geysers, detecting water, carbon dioxide and various hydrocarbons with its mass spectrometer, while also mapping surface features that are at much higher temperature than their surroundings with the infrared spectrometer.<ref name=NASA-20080325/> ''Cassini'' was unable to collect data with its cosmic dust analyzer due to an unknown software malfunction.

On November 21, 2009, ''Cassini'' made its eighth flyby of Enceladus,<ref name=PHYS-20091123/> this time with a different geometry, approaching within {{cvt|1600|km|mi}} of the surface. The Composite Infrared Spectrograph (CIRS) instrument produced a map of thermal emissions from the [[Tiger stripes (Enceladus)|Baghdad Sulcus 'tiger stripe']]. The data returned helped create a detailed and high resolution mosaic image of the southern part of the moon's Saturn-facing hemisphere.

On April 3, 2014, nearly ten years after ''Cassini'' entered Saturn's orbit, NASA reported evidence of a large salty internal ocean of liquid water in Enceladus. The presence of an internal salty ocean in contact with the moon's rocky core, places Enceladus "among the most likely places in the Solar System to host [[Astrobiology|alien microbial life]]".{{r|bbc5|Iess_2014|guardian1}} On June 30, 2014, NASA celebrated ten years of ''Cassini'' exploring Saturn and [[Moons of Saturn|its moons]], highlighting the discovery of water activity on Enceladus among other findings.<ref name=NASA-20140625/>

In September 2015, NASA announced that gravitational and imaging data from ''Cassini'' were used to analyze the [[libration]]s of Enceladus' orbit and determined that the moon's surface is not rigidly joined to its core, concluding that the underground ocean must therefore be global in extent.<ref name=NASA-20150915/>

On October 28, 2015, ''Cassini'' performed a close flyby of Enceladus, coming within  {{convert|49|km|mi|abbr=on}} of the surface, and passing through the [[Atmosphere of Enceladus|icy plume above the south pole]].<ref name=NASA-20151028/>

On December 14, 2023, astronomers reported the first time discovery, in the [[Plume (fluid dynamics)|plume]]s of Enceladus, of [[hydrogen cyanide]], a possible chemical essential for [[life]] as we know it, as well as other [[organic molecule]]s, some of which are yet to be better identified and understood. According to the researchers, "these [newly discovered] compounds could potentially support extant [[Microorganism|microbial communities]] or drive complex [[organic synthesis]] leading to the [[origin of life]]".{{r|NYT-20231214|Peter_2023}}