Matthew 24:29-30

29 "Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light; the stars will fall from heaven, and the powers of the heavens will be shaken.

30 Then the sign of the Son of Man will appear in heaven, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of heaven with power and great glory.