On Sept. 15, 2017, right before Cassini made its descent into Saturn, it took one last photo. And just like that, it was the end of the 20-year mission. So long, Cassini. Thanks for the memories.

On Sept. 15, 2017, right before Cassini made its descent into Saturn, it took one last photo. And just like that, it was the end of the 20-year mission. So long, Cassini. Thanks for the memories.