Nature: A new examination of satellite data has revealed that a 2005 drought in the Amazon basin was so severe that damage to the canopy remained four years later. Earlier studies using reflected solar radiation to determine the “greenness” of the basin provided contradictory results because clouds and aerosols could influence the data. Sassan Saatchi of the Jet Propulsion Laboratory in California used microwave satellite imagery of the area to measure the canopy’s structure instead of its greenness. Where the canopy was full, the images were smooth; where it was damaged, the images were rough. Saatchi found that more than 70 million hectares of rainforest were affected by the drought. By the time the satellite failed in 2009, much of that area had not returned to pre-drought conditions. Saatchi hopes to use a new satellite to examine the damage from another drought that occurred in 2010. He believes that if droughts become more frequent in the Amazon, it will be important to understand how the area continues to respond to the damage.