Here’s what you need to know about the 2017 eclipse. What is a solar eclipse? A solar eclipse happens when the moon lines up between the Earth and the sun as the Earth revolves around the sun. The moon blocks the sun’s light from reaching the Earth. Wait, doesn’t the moon move between the Earth and the sun every month? Yes, but we don’t have solar eclipses every month because the moon’s orbit is tilted by about five degrees, with respect to the Earth’s orbit around the sun. It’s only when the Earth, the sun and the moon line up just right that you have an eclipse. When is the solar eclipse? The eclipse will happen on Aug, 21. What time will the eclipse start? The totality -- more on that in a minute -- will reach the West Coast of the United States – between the Oregon cities of Newport and Lincoln City – at 10:16 a.m. PT. That is 1:16 ET. Source