An eclipse of the Sun occurs whenever the Moon passes directly in-between the Earth and the Sun. The celestial alignment causes the lunar orb to partially or completely obscure the Sun’s glowing face. This can happen because the Moon appears to be roughly the same size as the Sun when viewed from Earth. And as a result, the Moon casts its shadow on the planet to briefly turn day into night.
When is the next solar eclipse of the Sun?
The next solar eclipse is a total eclipse of the Sun on the evening of July 2, 2019, Universal Time.
Totality will peak around 8.24pm BST or 7.24pm UTC, 3.24pm EDT, 12.24pm PDT).
On Tuesday, July 2, the eclipse will start over the open waters of the Pacific Ocean.
It will then creep over South America’s Chile and Argentina, starting around 3.22pm Chile Time.
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How long will the solar eclipse last?
During so-called totality, the Sun’s glowing corona is completely obscured behind the Moon.
And according to Western Kentucky University (WKU) in the US, the longest a total eclipse of the Sun can last is up to seven minutes.
On Tuesday, space agency NASA expects totality to last up four minutes and 33 seconds, depending on the location.
This means the 2019 eclipse will be nearly twice as long as the spectacular August 2017 eclipse, which covered the US coast to coast.
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WKU explained: “The time of totality is always longest at the centre of the Moon’s shadow, decreasing for locations to the north and south of this centre line.
“There is also a difference for those on the centre line depending on location east to west.”
The exact timing of an eclipse is dependant on the relative position of the Earth and the Moon in their respective orbits.
In most cases, however, the differences amount to seconds.
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What is the path of totality for the eclipse?
The solar eclipse will start over the Pacific Ocean and cut diagonally through Chile and Argentina, from La Serena and pass just south of Buenos Aires.
NASA said: “The eclipse begins over the Pacific Ocean and the lunar shadow enters South America near La Serena, Chile at 3.22 pm EDT (3.22pm CLT). Totality begins in La Serena at 4.38pm EDT (4.38 pm CLT).
“The total eclipse will end near Chascomús, Buenos Aires, Argentina at 4.44pm EDT (5.44pm ART), not long before sunset at 5.24pm EDT (6.24pm ART).
“Outside this path, a partial solar eclipse will be visible in the rest of Chile and Argentina as well as Ecuador, Peru, Bolivia, Paraguay, Uruguay and parts of Colombia, Brazil, Venezuela and Panama.”