What does Revelation 8:12 mean?
To this point, three angels have sounded their trumpets, each resulting in horrible calamity on earth. Most of these seem to be focused on environmental issues: raining hail and fire, destruction of the sea, and poisoning of fresh waters. When the fourth angel blew his trumpet, stellar catastrophes occurred. A darkness covered a third of the sun, a third of the moon, and a third of the stars. A third of the naturally-occurring light was plunged into darkness.As was the case during the Exodus, these phenomena show God is in control of nature. The events described here would drastically affect crop growth, solar power, global climate, and energy use. Jesus predicted in Luke 21:25–26 that "there will be signs in sun and moon and stars, and on earth distress of nations in perplexity because of the roaring of the sea and waves, people fainting with fear and with foreboding of what is coming on the world. For the powers of the heavens will be shaken." Even earth's most renowned scientists will not be able to explain, and panic will seize earth's population.
However, this darkness might also provide a covering for righteous Jews to escape to the mountains when the false prophet sets up an image in the holy place, as described in other prophetic passages (Daniel 11:31; 12:11; Matthew 24:15–16; Revelation 13:1–15).