After 20 years in space and 13 years on the job as a scientific instrument orbiting Saturn, Cassini, the probe sent to explore the ringed planet and its moons, was retired at 7:55a.m. EST on Friday, September 15. But just before its final moments, before being torn apart by Saturn's atmosphere, Cassini once more did what it had been doing for two decades: it sent us some phenomenal photographs.
Before its final plunge into Saturn's atmosphere, Cassini had executed roughly four months of final orbits between the planet and its rings--something that had never been done before--and also took goodbye photographs of Saturn, Titan, and Enceladus, among others. The image gallery below has a few more of our favorites.
NASA decided to end Cassini's mission by sending the probe into Saturn's atmosphere because there was a fear of contaminating the planet's moons. The thinking was that microbes from Earth may have stowed away on board while Cassini was being built here on Earth, and because Cassini's insides are warm from its radioisotope thermoelectric generator (RTG), it's possible those microbes could still be alive and could taint worlds that may already have life. Crashing Cassini wouldn't necessarily kill the microbes, and the RTG could even help the probe to melt through surface ice into an underground water ocean.
We know that Titan and Enceladus have underground water oceans beneath their thick shells of ice because Cassini discovered them. Cassini was also responsible for discovering six named moons, generating nearly four thousand scientific papers, and taking roughly 453,000 photographs of celestial objects. Including this very last one (below) of Saturn itself, just before the atmosphere pulverized the probe, ending the 13 year long dance with a flash of eternal embrace. (When Cassini exploded, there was a flash, but no fire because Saturn's atmosphere doesn't have oxygen.)
Images that are just as potent as the ones from space are the ones from Cassini's mission team as they watched the final moments of the probe's life. It's hard to imagine a mission working more perfectly than this one, which is probably a big reason it's so hard to say goodbye.
What do you think of these final Cassini images? How are you handling the idea that we won't be getting any more images from Saturn for years to come? Let us know in the comments below.