According to the book, Jerusalem, one of the world’s oldest cities, last experienced a total solar eclipse on August 2, 1153, until August 6, 2241. wholeness By the late Fred Espenak, NASA’s preeminent solar eclipse calculator. The difference is 1,108 years. Meanwhile, people living in a roughly 32,400-square-mile (52,200-square-kilometer) quadrant of Illinois, Missouri, and Kentucky experienced totality twice in just six years, seven months, and 18 days.
Why are people in Perryville, Cape Girardeau, Paducah, Carbondale, Makanda, Harrisburg, and Metropolis all too accustomed to the big picture in their backyard, while people in Jerusalem have been so unhappy for generations? Why are some places on? earth Some humans have never seen a total solar eclipse in their lifetime, while others have a total solar eclipse path (usually about 100 miles wide) that crosses their home on a regular basis?
How often do total solar eclipses occur?
The frequency of total solar eclipses is difficult to determine because the intervals between total solar eclipses occurring in the same location are very irregular. Reference works are 1982 paper Written by Belgian astronomer Jean Meeus, a legend in mathematical astronomy. Meeus used one of the first computers available, the HP-85 personal computer, to calculate the entire path to the answer over the next 600 years. Generally accepted wisdom sums up solar eclipse They occur on average once every 360 years at a particular location on Earth, but that number dates back to an astronomy textbook in 1926, with no supporting calculations provided. Meeus’ calculations refined this figure to an average of 375 years. This number has been the standard ever since, but given advances in computing, recent efforts are trying to improve the number by processing more data in different ways.
NASA’s 5,000 year heat map
Ernie Wright of NASA’s Scientific Visualization Studio in March 2024, just before the second Great American Eclipse in seven years. published Heat map of total path across the globe. It includes the paths of 3,742 total solar eclipses spanning 5,000 years from 2,000 BC to 3,000 AD. 5th Millennium of Solar EclipsesA list of solar eclipses calculated by Jean Meeus and the late Fred Espenak, published in 2006. “It is clear from the heatmap that a total solar eclipse can absolutely occur anywhere on Earth,” Wright wrote. “In fact, there is no pixel on the map that does not experience at least one solar eclipse. There is not a single goose egg anywhere among the 14.6 million points sampled on the map.” Every pixel on Wright’s map experiences between one and 35 total solar eclipses every 5,000 years.
14,999 years of research in Time and Date
a paper The research was submitted to arXiv in February and accepted for publication in the British Astronomical Society Journal later this year. This is the most comprehensive effort, covering 35,538 solar eclipses over 14,999 years, a computing job that used 662,000 gigabyte hours of memory and 147,000 core hours for 102 consecutive days of computation. A new, sophisticated figure has been discovered. 373 years. “The Meeus figure has been widely cited, and we thought it would be interesting to see what would happen if we posed the same problem to a modern computer,” lead author Graham Jones, an astrophysicist and Time and Date science communicator, told Space.com. But this study not only improves on Meeus’ work, but also reveals deeper patterns in when and where total solar eclipses occur, related to Earth’s orbital mechanics.
“Latitude effect”
Both recent papers revealed previously only suspected patterns of when and where total solar eclipses occur. A surprising finding from the Time and Date paper is the “latitudinal effect,” whereby the frequency of solar eclipses of all kinds peaks near the Arctic and Antarctic circles and is lowest near the equator. The reason is simple. Near the polar circle, solar’s path begins to graze along the horizon at certain times of the year, extending the period during which an eclipse can occur.
Wright’s research for NASA found that total solar eclipses occur more often in the Northern Hemisphere than in the Southern Hemisphere, largely due to the Earth’s slightly elliptical orbit around the Sun. They also occur more frequently in the summer because the sun is out longer. “Summer in the Northern Hemisphere occurs when the Earth is near aphelion, the farthest point from the Sun throughout the year, so the Sun is a little smaller in the sky and the Moon is more likely to completely cover the Sun,” Wright wrote. However, the dates of aphelion and aphelion are perihelion (the time of the year when the Earth is closest to the Sun) it drifts for centuries. “There is a 21,000-year cycle in which aphelion and perihelion dates vary in the calendar, so about 4,500 years from now, aphelion and perihelion will coincide with the vernal equinox. At that stage, neither hemisphere has such an advantage in moving the sun closer or further away during the summer.” In about 9,500 years, this arrangement will reverse, and the dominance will shift to the southern hemisphere. This 21,000-year cycle explains why the actual interval between total solar eclipses in a given location remains highly irregular compared to the average.
What about the “Ring of Fire” annular solar eclipse?
Frequency of annular solar eclipses — new moon The farthest point from Earth blocks only the center of the sun’s disk, causing an annular solar eclipse. This was also featured in Meeus and Time and Date. The study revealed that annular solar eclipses occur, on average, once every 224 or 226 years, respectively, at a given location on Earth. Why are they more common than total solar eclipses? “Annular solar eclipses are more common because, when you calculate the average size of the Sun and Moon across all eclipses, the Sun is typically only slightly larger than the Moon,” Jones says.
This trend will continue to increase. The reason why a total solar eclipse occurs is month And the sun can have the same apparent size in Earth’s sky. The Sun is about 400 times wider than the Moon, while the Moon is about 400 times closer. However, the moon slowly moving away from the earth It is increasing by 1.5 inches (3.8 centimeters) per year, which has devastating effects for those who chase the eclipse. “Over very long time scales, total solar eclipses will eventually stop completely as the moon slowly moves away.” The good news? That won’t happen for about 600 million years.