alt Hacker News> This remarkable transformation in our understanding is the result of just three missions: Voyager, Galileo, and Cassini—along with some computer modeling and hard staring by the Hubble and Webb space telescopes.
Seems odd to neglect to mention New Horizons immediately after mentioning the probable existence of liquid oceans under Pluto's surface, a finding made possible thanks primarily to New Horizons.
No shade on New Horizons intended, but I was talking about the early 2000's revolution in understanding of ice moons/ocean worlds, and that preceded the Pluto flyby by a lot.
It was a valuable piece of corroborating evidence, but not shocking and unexpected in the way results from those three missions were. We had good reason to believe Pluto would look a lot like Triton, and it does.