Looking to the future, many of Cassini's scientists are eager to return with new, more capable spacecraft.
On Thursday, other Cassini instruments will make detailed, high-resolution observations of Saturn's auroras, temperature, and the vortices at the planet's poles. That's because scientists have been able to "pursue questions that we never thought Cassini would have the opportunity to answer", he said. Eight of its 12 science instruments will be operating, allowing the spacecraft to directly sample the composition of the atmosphere and potentially returning insights into the giant planet's formation and evolution. The probe arrived in 2004, and has studied the planet, its rings of ice and dust, and collection of mysterious moons ever since. Cassini found fluffy lumps of material the size of mountains in two of Saturn's rings. The little spacecraft that could will continue to transmit for as long as it possibly can, firing its control thrusters in short bursts as it enters the atmosphere. "Between Voyager and Cassini was 30 years", Green said.
The data that resulted in the discovery of the dust-free gap between Saturn and its rings is just one of the many tidbits of information that Cassini has sent back to astronomers here on Earth.
"The spacecraft's final signal will be like an echo", said Earl Maize, Cassini project manager. Mission scientists learned to use Titan as a dance partner for the spacecraft, dipping into the moon's gravitational potential to fling Cassini onto new trajectories while conserving precious fuel.
The scientists wanted to get their money's worth from the £2.9 billion mission and so packed Cassini with instruments, leading to comparisons with a multi-purpose Swiss army knife. It arrived six years later, having navigated the unsafe asteroid-belt that lies between us and Saturn, but with only basic instrumentation on board it wasn't able to gather much scientific data.
One of Cassini's chief discoveries was a global watery ocean beneath the icy surface of Saturn's moon Enceladus.
While orbiting Saturn almost 300 times, Cassini made major discoveries, such as the liquid methane seas of the planet's giant moon Titan and the sprawling subsurface ocean of Enceladus, a small Saturn moon.
For the scientists who began working on the project in the 1980s, it is the end of decades of work culminating in scientific progress and never-before-seen images of Saturn's rings, moons and surface.
Cassini was the NASA-developed Saturn orbiter, and Huygens was the European-built probe that sat on-board, which would eventually descend on to the surface of Saturn's biggest moon, Titan.
With this view, Cassini captured one of its last looks at Saturn and its main rings from a distance.
Cassini is in the process of taking its final pictures of the Saturnian system.
What was the goal of the Cassini mission?
To study Saturn and its moons up close. The Grand Finale is necessitated to prevent the possibility of Earthly bacteria that has been living on Cassini for the last 20 years contaminating an object orbiting Saturn - an unlikely but possible occurrence.
With the end of Cassini, there is no other mission now operating or under development to visit Saturn or its moons.