Why will the April 8 eclipse not be repeated until 54 years later?

United States – When the Moon’s central shadow moves at more than 2,400 km/h across North America in a total solar eclipse on April 8, the spectacle will be very unique.

This total path (the path of the moon’s dark shadow across the face of the Earth) will be narrow, only 185 km (115 miles) wide, and will cross parts of Mexico, the United States and Canada in a path that will never be repeated across the continent, and will last for only 100 minutes.

Only from within this path will viewers encounter darkness during the day, lower temperatures, and a change in animal behavior. Also, only within this path will it be possible to look at the beautiful, completely eclipsed sun’s corona with the naked eye, with the need to be careful not to look directly at the sun at any time. Time without wearing a pair of approved solar eclipse glasses.

For most of the 40 million people living in the path of totality, this will be a once-in-a-lifetime event. Considering that this event is on the same current path and will not be repeated until 54 years later.

The solar eclipse occurs within a group known as the “Saros cycle,” which is a period equivalent to approximately 223 lunar months, according to the moon’s orbits around the Earth. This is equivalent to 6585.3 days, or 18 years, 11 days, and 8 hours, according to NASA.

During the “Saros cycle,” the same geometric arrangement of the sun, moon, and Earth is repeated. A cycle refers to a group of successive eclipses and eclipses that can be viewed from specific areas of the Earth.

Eclipses and eclipses belonging to the same “Saros cycle” are similar, and are identified by their Saros series number.

The total solar eclipse on April 8 is part of the “Saros cycle” 139, which was responsible for the total solar eclipse across Africa 18 years, 11 days and 8 hours ago, on March 29, 2006, on April 8, 2024, and on April 20, 2042. The “Saros cycle” is a total solar eclipse in Asia.

According to scientists, the eight hours within the “Saros cycle” ensure that the total path similar to the eclipse will reappear in the same part of the Earth following every fourth repetition. This period, which consists of precisely 669 moons, or 54 years and 33 days, is called exligmos.

So the same celestial mechanics that cause the total solar eclipse on April 8 produced a total solar eclipse in North America on March 7, 1970. This path of totality occurred slightly to the east, passing through Mexico, the United States (Florida, Georgia, North Carolina and Massachusetts) and Canada (Nova Scotia and Newfoundland).

After April 8, the total eclipse will visit North America and Mexico once more on May 11, 2078.

According to the “Space” website, the “Saros cycle” does not last forever, and over the centuries, it rises and falls across the surface of the Earth. Saros has produced 139 solar eclipses since the year 1501 and will continue until the year 2763, but it will reach its peak on July 16, 2186, when it will produce a total eclipse that will last for 7 minutes and 29 seconds, which is the longest total eclipse in 10,000 years, and until at least the year 6000.

Source: Space