What's the largest river on Earth? If you said "the Amazon".... you're only half right. Scientists have discovered an even bigger river in South America, and it's in the sky above the Amazon rainforest. Turns out, this sky river is the reason there's a rainforest at all....

Originally released by Knowledgemotion, 2018. Streaming video file encoded with permission for digital streaming by Infobase on February 21, 2020.

The Largest River On Earth Is In The Sky (5:30); .