A new documentary looks back at the triumphs of the Cassini probe — which has spent more than a decade revealing the secrets of Saturn — ahead of the spacecraft's scheduled death dive into the ringed planet.
Cassini captured the public imagination with its stunning images of the gas giant Saturn and its up-close examination of the planet's flowing ring system. Over the years, the probe discovered new moons around Saturn, and dug deep into the strange environments of the two largest Saturnian satellites.
"Kingdom of Saturn: Cassini's Epic Quest" reviews the historical figures who laid the groundwork for the mission, the probe's major discoveries, and how the probe connected with people on Earth. The movie is available to watch now on Amazon. [Cassini's 'Grand Finale' at Saturn: NASA's Plan in Pictures]
Cassini left Earth in October 1997 as part of the Cassini-Huygens mission, a joint effort by NASA and the European Space Agency (with a leading role played by the Italian Space Agency). The Huygens probe was dropped onto Saturn's moon Titan in January 2005, about six months after arriving at Saturn. Since 2008, Cassini has been operating on extended scientific missions. Now that the probe is running out of fuel, scientists have decided to crash the probe into Saturn. This will not only provide a close-up glimpse of the planet and its rings, but will also guarantee that the probe will never accidentally crash into one of the planet's potentially habitable moons.
"Kingdom of Saturn" provides a tour of the planet and its rings, highlighting fascinating details like the hexagonal cloud formation at its north pole, and its extraordinary system of rings, which are 30 million times wider than they are high.
"[Cassini] has traveled nearly 4 billion kilometers [2.48 billion miles], delivered a probe to the surface of a toxic moon, spent 20 Earth years in space, and produced science nine years longer than originally planned," the film's narrator says, summarizing some of Cassini's major accomplishments. "[Cassini] has discovered flowing water where none was expected, phantasmagorical structures on a planet’s icy rings, a weirdly breathing magnetosphere, and a possible abode of life on a tiny world with a startling atmosphere." [Cassini's 'Grand Finale' Saturn Orbits Explained (Video)]
The movie also shows viewers how Cassini's investigations of Saturn have not only helped scientists understand Earth's solar system, but also planetary systems around other stars. Saturn itself is an example of the gas giants that have now been found around thousands of stars, and Cassini has helped scientists better understand how these monsters form.
"The science based on Cassini's data will go on for decades," the film's narrator says.
Since Cassini arrived at Saturn, scientists have found more evidence that the planet's moons Enceladus and Titan could potentially host life. Enceladus may possess a liquid water ocean beneath its icy surface, with a geologic source of heat. Geysers of water spew up through cracks in the moon's surface, and Cassini flew through one of the geysers and sampled its composition. Titan's surface is mostly covered in liquid methane and ethane, rather than water, which means "if anything lives on Titan, it is almost surely not related to life on Earth," according to the documentary. The documentary dives deep into Cassini's investigation of these particularly interesting moons.
The documentary doesn't keep its focus exclusively on space; it covers the historical figures after whom the Cassini and Huygens probes are named, and it touches on the time just before Cassini's launch when protesters urged NASA and ESA to cancel the mission over fears the launch rocket might explode and release the radioactive material contained inside the probe. (Cassini-Huygens, like many space probes, carried radioactive material as a source of heat and energy.)
Cassini will make its final death dive on Sept. 15, 2017, at 5 p.m. EDT (2100 GMT). Check out "Kingdom of Saturn" before the world says goodbye to the Saturn probe forever.