Watch live coverage from NASA of the total solar eclipse. Those in the path of totality, where the moon’s shadow completely blocks the sun, will see the sky darken like dusk. NASA says the sun’s outer atmosphere will also be visible, weather permitting. The 115-mile-wide path of totality stretches from Mexico through 15 U.S. states — from Texas to Maine — and on up to Canada. Totality will last for up to 4 minutes and 28 seconds.