Tens of thousands have gathered to gaze at a total solar eclipse across northern Chile, one of the world's best spots to see the cosmic spectacle.
Tens of thousands of tourists have flocked to cities and towns across northern Chile to stake out spots in one of the world's best locations ahead of a total solar eclipse on Tuesday.
The rare cosmic spectacle will begin at 10:24 am local time in the South Pacific (3:30 am AEST) and sweep along an 11,000km path across open waters to Chile and Argentina, the only places that the total eclipse will be seen aside from an uninhabited island out in the ocean.
The eclipse is expected to make its first landfall in Chile at 3:22 pm in La Serena (5:22 am AEST), a city of 200,000 people.
The total eclipse will begin there at 4:38 pm and last about two minutes.
"I came to La Serena to watch the total eclipse with a friend following a recommendation," US tourist Stephanie Bouckurt said.
"They told me that nothing compares to a solar eclipse, so that's why we're here. We're super excited."
It's the first time in 13 years South America has experienced a total solar eclipse, two years after a solar eclipse went coast-to-coast over the US.
Authorities on alert
Authorities and businesses have prepared for the arrival of more than 300,000 visitors, with the local water company forced to increase output while service stations are storing extra fuel.
Extra police and health services have also been reinforced.
Northern Chile is known for clear skies and some of the largest, most powerful telescopes on Earth are being built in the area, turning the South American country into a global astronomy hub.
The town of La Higuera will also be plunged into total darkness.
"We hope this milestone will transform (our town) into a tourist attraction, so that visitors can come to La Higuera and take a picture where there once was a total sun eclipse," Mayor Yerko Galleguillos said.
Town officials distributed more than 2000 cardboard-frame protective eyeglasses at local schools and community centres and workers built statues of huge sunglasses and a darkened sun on a local square.
"These glasses are going to give (students) the opportunity to protect themselves and witness this spectacle that we've all been waiting for so eagerly," director of the Juan Pablo Munoz school Alejandra Zuniga said.
What is a solar eclipse?
A solar eclipse occurs when the moon passes between the Earth and the sun and scores a bull's-eye by completely blocking out the sunlight.
A total solar eclipse is when the moon passes in front of the sun blocking light from reaching Earth. Astronomers take advantage of solar eclipses to study the corona, the sun's top layer.
Even though the moon is 400 times smaller than the sun, the rare cosmic coincidence makes the sun and moon appear to be the same size.