The gaping hole in Earth's ozone layer has shrunk 30 percent in size compared to last year, according to new measurements made by the European Space Agency's Envisat satellite.

The ozone layer loses about 0.3 percent of its mass annually, yet fluctuates in its thinness through the year. The region of extremely reduced ozone above Antarctica, popularly known as a "hole," generally peaks in size during September and October but regains its composure by the New Year.

Researchers are not certain if this year's smaller ozone hole means the radiation-blocking layer is healing.