What Holds the Record for the Longest Solar Eclipse, and How Does the Upcoming April 2024 Total Eclipse Measure Up?
On April 8, 2024, a total solar eclipse will grace parts of Mexico, the U.S., and Canada, with all of North America witnessing at least a partial solar eclipse. The maximum totality duration, when the moon completely blocks the sun’s face, will be 4 minutes and 28 seconds, occurring near the village of Nazas in northwestern Mexico. Although this is a substantial duration, it falls short of the longest solar eclipse in history.
The record for the longest totality goes to June 15, 743 B.C., where a solar eclipse lasted 7 minutes and 28 seconds. This event took place in the Indian Ocean off the coast of Kenya and Somalia. Theoretically, the maximum totality achievable on Earth is 7 minutes and 31 seconds, mathematically calculated by eclipse expert Jean Meeus. This scenario occurs within 5 degrees north of the equator in July when the sun is at aphelion, its farthest point from Earth, and the moon is at perigee, its closest point to Earth. However, no record exists of such a lengthy eclipse happening in the last several thousand years.
Looking into the future, the prediction for a solar eclipse on July 16, 2186, over the Atlantic Ocean off the coast of French Guiana anticipates a totality lasting 7 minutes and 29 seconds. This eclipse, resulting from Saros 139, a family of solar eclipses occurring every 18 years, 11 days, and eight hours, is expected to be exceptional due to the moon’s proximity and the sun’s distance. Eclipses of extreme duration have common characteristics: they occur in July when the sun is farthest from Earth and close to the equator.
Notably, a historic moment in eclipse-chasing involved seven scientists aboard the supersonic jet Concorde 001 on June 30, 1973. Flying at Mach 2, they extended totality on the ground in Niger from 7 minutes and 4 seconds to an astounding 74 minutes.
Looking ahead, Saros 136 will produce three more total solar eclipses of extraordinary duration on Aug. 2, 2027 (maximum totality of 6 minutes and 23 seconds near Luxor, Egypt), Aug. 12, 2045 (maximum totality of 6 minutes and 6 seconds off the coast of Florida and the Bahamas), and Aug. 24, 2063 (maximum totality of 5 minutes and 49 seconds in the North Pacific Ocean). The longest totality of the 21st century occurred on July 22, 2009, lasting 6 minutes and 39 seconds, near Japan’s Ishinomura-Kitaio Island.”