↠ Check out our Climate Heroes series: https://www.youtube.com/playlist?list=PLZ3CjNbCdQe8dN8YtA54vfnkWVejclPhR In Canada, a beaver family has built a dam extending 850m - that's more than twice as long as the Hoover Dam. It's so big it can be seen from outer space. But that's not the only reason NASA is interested in this architecturally minded species...