Cassini's observations of Titan have revealed the moon to be one of the most interesting bodies in our solar system.
Just a few days before it is due to plummet into the fiery atmosphere of Saturn on its self-destruct mission, Cassini has completed its final flyby of the moon Titan.
The spacecraft passed Titan at 73,974 miles (119,049 kilometres) above the moon's surface, in a symbolic 'goodbye kiss' flyby that will provide the spacecraft with one last nudge of gravitational energy to send it to its end.
On Friday, the 15th September, Cassini will send itself into Saturn, almost 20 years since it left Earth. Its self-destruction will ensure Saturn's moons remain unharmed by the remnants of the spacecraft, as some of the moons are thought to be the most likely places in the solar system for life to have developed.
It is quite apt that Cassini will use Titan for its final plunge because, in its 13 years orbiting Saturn, Cassini's observations of Titan have revealed the moon to be one of the most interesting bodies in our solar system.
"Cassini has been in a long-term relationship with Titan, with a new rendezvous nearly every month for more than a decade," said Cassini Project Manager Earl Maize at NASA's Jet Propulsion Laboratory in Pasadena, California.
"This final encounter is something of a bittersweet goodbye, but as it has done throughout the mission, Titan's gravity is once again sending Cassini where we need it to go."
Cassini data revealed Saturn's largest moon, Titan, has liquid methane oceans on its surface, lying underneath a thick nitrogen-rich atmosphere. The moon is the only body to undergo a cycle similar to the water cycle on Earth, except on the extremely cold Titan it rains methane from hydrocarbon clouds.
Cassini's discoveries completely rewrote our understanding of the remarkably Earth-like world of Titan; before 2004 all we knew was the moon had a thick atmosphere. Many of these discoveries were made possible by the Huygens probe, which Cassini carried from Earth and released to descend onto the planet in 2005.
Cassini's missions have revolutionised our understanding of Saturn, giving us a portal to look at the processes that shaped the development of our solar system, as well as planetary systems around other stars.
In its final few moments, Cassini will continue to gather new information on Saturn as it passes by the planet's iconic rings – giving us a closer glimpse than ever before.
Cassini will collect vital data that was too risky to obtain earlier in the mission including detailed maps of Saturn's gravity and magnetic fields and extreme close-ups of Saturn's rings and clouds.
As it descends onto the planet, at around 940 miles (1,510 kilometres) above Saturn's cloud tops, communication with Earth will cease, and the spacecraft will break up like a meteor moments later. This is expected to take place at 7:54 a.m. EDT (12:44 p.m. BST).
Cassini will have been destroyed for about 83 minutes before its final signal reaches NASA's Deep Space Network's Canberra station in Australia.