These are the last close-up photos of Saturn we may see in decades
Cassini is scheduled to die Friday around 6:22 a.m. EDT, though news of its destruction will take about 1 hour and 23 minutes to reach NASA. (The planet is 930 million miles away.) While it's very unlikely telescopes on Earth will record the event, NASA TV is broadcasting live from the Cassini control room during that time.
NASA is killing its only Saturn probe because it discovered oceans which may harbor alien life on Enceladus and Titan - two of Saturn's largest moons. Cassini has nearly run out of propellant, and the space agency wants to avoid crashing into and contaminating the moons; thus, the nuclear-powered probe is being put down.
It may be decades until Earth receives views as crisp and stunning as those returned by Cassini. Even if NASA funds a new Saturn mission in 2019, that spacecraft would launch in 2024 - then it'd take years to make the trip. (Cassini launched from Earth in 1997 and arrived at Saturn in 2004.)
The download of Cassini's last pictures, which began around 5:45 p.m. EDT on Thursday, should take about 11 hours to finish. Linda Spilker, a Cassini project scientist and a planetary scientist at NASA JPL, told reporters on Wednesday that these images are "the final picture postcards of the Saturn system."
Here are some of Cassini's final photos uploaded to the mission's raw image gallery and processed by space fans on social media.