Alaska's pristine rivers are turning a rusty orange even when seen from space, likely because of melting permafrost: study

• Scientists say that dozens of waterways in Alaska are "rusting," or turning into a dirty orange.
• They said permafrost thawing in the summer is now exposing minerals to the surface, releasing metals and acid.
• Some brooks and streams are turning so acidic that they're comparable to lemon or orange juice.

At least 75 of Alaska's brooks and streams have been turning a dirty orange likely due to thawing permafrost, with some rivers so impacted that the discoloration can be seen via satellite, a new study says.