Why are trees and other plants green? Seems like a simple question, but the answer is full of surprises. Using a special camera that can pick up light just beyond the visible range, into the near-infrared, viewers get to see trees like never before. These otherworldly images can reveal not only why trees are green on Earth, but what color photosynthetic life on other planets might be. Part of the "It's Okay to Be Smart" series.