A total solar eclipse occurred at the Moon's ascending node of the orbit on Friday, July 31, 1981. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. The continental path of totality fell entirely within the Soviet Union, belonging to Georgia, Kazakhstan and Russia today. The southern part of Mount Elbrus, the highest mountain in Europe, also lies in the path of totality. Occurring only 3.8 days after perigee (Perigee on July 27, 1981), the Moon's apparent diameter was larger. With a path width of 107.8 km (66.984 mi, or 353,674.541 feet), this total solar eclipse had an average path.