Southern Pacific Total Solar Eclipse

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People travel thousands of miles to catch the celestial intersection of sun and moon, which some describe as a spiritual high. On Sunday, July 11, it happens again.

When the moon blots out the sun’s blinding rays on Sunday, a sliver of the Earth’s surface will be plunged into eerie darkness.

Travelers who have crossed thousands of miles to witness the celestial show will gaze at the sky and, for a few minutes, see a thing most people never get to see: a halo of fire — the sun’s corona — flickering around the edges of the silhouette of the moon.

The coming total solar eclipse on Sunday may only be visible to a lucky cadre of die-hard skywatchers spread across the southern Pacific Ocean, but that hasn’t dampened spirits at remote spots like Easter Island – where tourists and scientists have flocked to catch the celestial show.

The best seats on Earth for the total solar eclipse are on Easter Island and other islands and atolls along a southern Pacific Ocean path that stretches from a spot just north of New Zealand to the tip of South America. Thousands of tourists are expected to flock to Easter Island alone, drawn by both the looming cosmic show and the island’s mysterious history.

“Here on Easter Island, I am very hopeful,” Williams College astronomer Jay Pasachoff told SPACE.com from the remote location. Pasachoff and two students flew out to Easter Island to observe the total solar eclipse to study the sun’s corona.

Solar eclipses are an extreme rarity within the universe at large. They are seen on Earth because of a fortuitous combination of circumstances. Even on Earth, eclipses of the type familiar to people today are a temporary (on a geological time scale) phenomenon. Many millions of years in the past, the Moon was too close to the Earth to precisely occlude the Sun as it does during eclipses today; and many millions of years in the future, it will be too far away to do so.

Due to tidal acceleration, the orbit of the Moon around the Earth becomes approximately 3.8 cm more distant each year. It is estimated that in 600 million years, the distance from the Earth to the Moon will have increased by 23,500 km, meaning that it will no longer be able to completely cover the Sun’s disk. This will be true even when the Moon is at perigee, and the Earth at aphelion.

A complicating factor is that the Sun will increase in size over this timescale. This makes it even more unlikely that the Moon will be able to cause a total eclipse. Therefore the last total solar eclipse on Earth will occur in slightly less than 600 million years.