Something strange happened over the Arctic this year when a hole developed in the ozone layer. The European Commission's Copernicus satellite program tracked the unusual occurrence, and now has evidence that the hole healed itself.
The ozone layer acts like sunscreen for the Earth, protecting life from harmful ultraviolet radiation. The most famous ozone hole is the one that occurs annually in the Antarctic.
The discovery of the Antarctica ozone hole spurred a global effort to reduce the use of harmful chemicals that contribute to the opening. The Arctic hole, however, isn't traced to human activity, but to what the European Space Agency called "unusual atmospheric conditions," including a powerful polar vortex of swirling cold air.