Earth's forests play a critical role in keeping our planet habitable. Often called the "lungs of the Earth," forests cover nearly one-third of the planet and absorb vast amounts of carbon dioxide from the atmosphere.

Scientists say the radar will paint the first detailed global map of forests’ biomass, which is crucial for sucking up carbon and slowing climate change.

Mapping the world's forests, said to include some 1.5 trillion trees, is a big, big job—one that will be made a whole lot easier with Europe's newly launched satellite. The European Space Agency on Tuesday launched Biomass,