The pictures come down looking like black-and-white photographs, but they’re actually multiple views taken through different filters. NASA will eventually come up with the “official” color combination, but in the meantime, Lakdawalla and others who are adept at image processing are putting out their own versions – sometimes after multiple tries:
I posted that and instantly realized something was wrong. It's summer in the northern hemisphere. It's upside down! Here it is right side up pic.twitter.com/tfyxFspaKA
There’ll be much, much more to come in the hours ahead, but pictures won’t be the last things that Cassini sends back: Toward the end, the spacecraft will switch to sending data about the composition of Saturn’s upper atmosphere, magnetosphere and radio environment, at a transmission rate that’s low enough to make sure the data’s received by radio antennas back on Earth.
The end will come at 4:55 a.m. PT Friday, when Cassini dips so low into the atmosphere, at such a blazingly fast speed of 76,000 mph, that the spacecraft breaks up and vaporizes.
It’s all part of NASA’s plan to dispose of the orbiter in such a way that there’s no risk of contaminating Enceladus or Saturn’s smog-covered moon Titan, another potential home for alien life. Those moons are likely to be the focus of future space missions, and scientists want to make sure their natural state is preserved for when that day comes.
A similar scenario played out in 2003, when NASA’s Galileo orbiter dove to its destruction in Jupiter’s atmosphere. That was done to make sure that spacecraft didn’t smash into Europa, an ice-covered Jovian moon that’s thought to harbor a hidden ocean.
Now NASA’s Europa Clipper is due to head out in the 2020s to take a fresh look at that moon – and if the stars align, someday a future space probe will catch a closeup of Enceladus and Titan rising again.