The total lunar eclipse of July 6, 1982, was the longest lunar eclipse of the 20th century, with totality lasting 1 hour 45 minutes 44 seconds. Visible across Australia, the Pacific, the Americas, and western Africa, the eclipse was dramatically impacted by the March-April 1982 eruption of El Chichón volcano, in Mexico. A volcanic eruption injects sulfur dioxide and water vapor into the stratosphere, creating a haze of sulfuric acid. Such a cloud can persist for years, filtering sunlight, impacting surface temperatures, reducing solar radiation, and creating unusually brilliantly colored sunrises and sunsets. During the lunar eclipse of 1982, it also gave the Moon a distinct appearance: the top and middle were darker, while the bottom was shaded in red. The noticeably blacker appearance of the Moon’s upper half suggested that volcanic aerosols were more present in the Northern Hemisphere.
