Why NASA wants you to point your smartphone at trees

NASA would like you to take a picture of a tree, please. The space agency’s ICESat-2 satellite estimates the height of trees from space, and NASA has created a new tool for citizen scientists that can help check those measurements from the ground. All it takes is a smartphone, the app, an optional tape measure, and a tree.Launched in September 2018, the ICESat-2 satellite carries an instrument called ATLAS that shoots 60,000 pulses of light at the Earth’s surface every second it orb