Next God will send a tremendous earthquake that will rock the whole world (cf. Luke 21:11). The darkening of the sun (cf. Isaiah 13:10; Ezekiel 32:7-8; Joel 2:10; Joel 2:31; Amos 8:9; Matthew 24:29; Mark 13:24-25; Luke 21:25), the reddening of the moon (cf. Joel 2:31; Acts 2:20), and the falling of the stars to earth (a meteor-like shower?) appear from the context to be consequences of this judgment. A less likely possibility is that they will be unrelated phenomena. [source][source][source]
That the stars do not literally fall but appear to do so seems clear from the fact that they are still in place in Revelation 8:12. This fact suggests that we should also understand the other phenomena described here as appearing to happen, how these things will look as people on earth view them. [source][source][source]
Many commentators have taken this description as picturing a metaphorical convulsion among the nations, not a literal shaking of the earth and the heavens. Beale, for example, saw it as a metaphor describing God"s judgment of all sinners just before the last judgment, which he saw taking place at Christ"s second coming. [1] We should probably take them literally for at least two reasons. First, Jesus used the same language in the Olivet Discourse and gave no indication that it was symbolic (cf. Matthew 24:7; Mark 13:8; Luke 21:11). Second, a shaking of the nations follows in Revelation 6:15-17. [source][source][source]