The discoveries spacecraft Cassini has found during it’s mission of touring the Saturn system have included a global ocean with indications of hydrothermal activity within Enceladus and liquid methane seas on Titan. Cassini has dived in between Saturn and it’s rings 22 times and had it’s initial mission extended twice from 4 years to two decades.

It’s final end is on September 15th, 2017 as it changes it’s course and plunges into Saturn.

Read more here about Cassini’s mission

Source: NASA.GOV