It's been almost two years since the last total solar eclipse passed over the US, but there's a good chance you remember all of the hype. Now, a total solar eclipse is heading for parts of Chile and Argentina. It will arrive tomorrow, and thanks to NASA and the Exploratorium, you can catch a livestream as it happens. Beginning at 3pm ET, the agency will stream the eclipse, and at 4pm ET it will begin commentary in both English and Spanish. All three streams will be available on NASA's website.