Astronomical Signs

The sun is in a constant state of nuclear fusion where temperatures reach 6,000oC on its surface and 15,000,000oC at its core! The energy produced is unimaginable, and so is the idea that it will instantly be 'darkened'. One explanation is a total eclipse, but that would darken the sun only on a small portion of the earth and for a brief period of time.

Another explanation may be the Trumpet judgments in Revelation 8 that speak of comet/asteroid like objects crashing to the earth and stirring up dust that may explain the darkened heavenly spheres.