Using a NASA aircraft which flies over the Arctic, Harvard scientists have made observations of a molecule which is believed to be responsible for destroying stratospheric ozone. The substance is called chlorine peroxide, and it's formed from industrial materials used in refrigeration. These have been banned for several years, but they can persist in the high atmosphere for decades. This new data will allow scientists to better forecast the future degradation of the ozone layer, and regions which might let in more solar radiation.