Saturn's strangest sights, as captured by a doomed spacecraft

The Cassini-Huygens spacecraft will make its plunge into Saturn's atmosphere on September 15, after 20 years in space.

Cassini will go down in history for being the first spacecraft to orbit Saturn. That's when NASA guided Cassini into an orbital path that took it, for the first time ever, between Saturn and its rings. Navigators will also be analyzing this information in the hopes of confirming that Cassini is precisely on track and ready to plunge into Saturn at the designated time, location, and altitude. The infrared glow shows how hot a planet's atmosphere is, which can help explain many other phenomena on the planet such as storms or chemical composition. The huge outer "E" ring forms from the icy plumes that spray from the unexpectedly active Enceladus. On its way through the gas giant's upper atmosphere, Cassini will pulse its thrusters to keep its antennae pointed at Earth in order to transmit scientific data until tis final moments. "But Cassini will not go quietly". It's logged 4.9 billion miles, sent back almost half a million images of the ringed planet and its moons, and transmitted 635 gigabytes worth of scientific data so far.

Earl Maize, an engineer at NASA's Jet Propulsion Laboratory said: "We'll be saddened, there's no doubt about it, at the loss of such an incredible machine". Cassini also carried the Huygens probe, which landed on Titan, Saturn's largest moon, in 2005 and sent data about the moon's surface and atmosphere to Cassini for 72 minutes before the signal was interrupted by the horizon. The long duration of the mission allowed Cassini to study the moons in greater detail, such as Tethys which has a surface comprised of ice.

The Canberra space complex was given the key role of transmitting Cassini's final images of Saturn because the planet will be hovering above Australia on Friday.

The countdown has begun for the NASA's Cassini spacecraft will take its last dive in Saturn tomorrow (15 September).

JPL Cassini Project Scientist Linda Spilker compared Cassini's grand finale to "a last look around your house or apartment just before you move out", when "memories across the years come flooding back". During its final dive, the spacecraft will collect detailed maps of Saturn's magnetic fields and gravity which will reveal some interesting facts about the internal arrangements of Saturn which could solve the mystery of the fast rotation of the ring planet.

Inspired to learn more after flybys of Saturn by NASA's Voyager missions, the Cassini mission was created to be an global effort that united NASA, the European Space Agency (ESA) and the Italian Space Agency.

An illustration of NASA's Cassini spacecraft flying through the water plumes of Saturn's icy moon Enceladus.       NASA  JPL-Caltech
An illustration of NASA's Cassini spacecraft flying through the water plumes of Saturn's icy moon Enceladus. NASA JPL-Caltech

Ian Griffin says Cassini has had an awesome mission which has transformed our understanding of Saturn. Why is the program ending now after 13 years?

"Just as I was inspired as a kid by watching Apollo 11 land on the Moon, today's school kids have the opportunity to witness the spectacular finale of Cassini zooming through Saturn's rings".

Cassini is quickly running out of rocket fuel, and if left to its own devices, the orbiter would wander around the Saturn system uncontrolled, eventually crashing into whatever body that's unlucky enough to be in its way.

Launched in October 1997, Cassini took seven years to reach Saturn in July 2004, carrying with it a small European Space Agency lander called Huygens.

NASA recreated a Cassini image of a backlit Saturn using a collage of about 1,600 photos of people waving at the ringed planet as part of social media campaign in 2013. "It's one of the things we expected to learn, but have not". These and other pictures from orbiting Cassini confirmed that Titan has lakes, rivers and seas filled not with water, but liquid methane and ethane.

"Cassini has transformed our thinking in so many ways, but especially with regard to surprising places in the solar system where life could potentially gain a foothold", said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate, in a statement.

  • Joey Payne