WATCH: South America Total Solar Eclipse Live, Tuesday

Starting at 1:00 p.m. PDT on Tuesday, some lucky spectators  in parts of Chile and Argentina will get a chance to watch a total solar eclipse. It's a rare event where the moon entirely obscures thedisc of the sun (known as totality), leaving a glowing celestial crown.

Not in South America for the total solar eclipse? No worries, you can still watch it via the Exploratorium's  feed, right above. The museum will pick up a live stream from the telescope at Cerro Tololo Observatory in Chile.

Locals can also attend the solar eclipse event in person at the Exploratorium, with commentary in English and Spanish. There's an eclipse app, too.

The Great American Eclipse of 2017  was the last event that granted Americans (in certain parts of the country) a chance to witness a total solar eclipse.

What is a total solar eclipse?

Eclipses are possible thanks to a happy coincidence: The Sun is 400 times the diameter of the moon, while also being 400 times farther away from Earth. To us, both the moon and the Sun appear to be the same size allowing the moon to block light from the sun during solar eclipses.


A  total solar eclipse occurs when the moon moves directly between the sun and Earth,  preventing the sun's light from reaching the planet. When the three celestial bodies line up, the moon casts a shadow on a narrow band of the earth's surface, with a ring of light around the moon. The sky becomes dark, simulating the night sky. You can watch a simulated total solar eclipse in this animated view from space.