The rains on Titan...
Old news again! Evidence for Rain on Titan. I find it rather wonderful to think that all this time Titan has had seasonal rains and we didn't know. When I was in high school, rain on Titan. When Pluto was discovered, unobserved rain on Titan.
Back in 1655 when Titan was first discovered, quite possibly there was a downpour of methane happening that Huygens couldn't see. Amazing. Wonderful.