Eons Season 2018 Episode 19 That Time It Rained for Two Million Years ( Air Date 2018-05-22 ) Genre Documentary category. Overview "At the beginning of the Triassic Period, with the continents locked together from pole-to-pole in the supercontinent of Pangea, the world is hot, flat, and very, very dry. But then 234 million years ago, the climate suddenly changed for the wetter.".