The fearful signs in the heavens alluded to in Acts 2:19-20 and Luke 21:10-12 may refer to the aftermath of volcanic eruptions. Volcanic and seismic activity seems to be on the increase. There are perhaps hundreds of volcanoes under the ocean. Scientific observation of the heavens has generated the re-writing of astronomy textbooks. Sightings of asteroids, meteorites, and other near earth objects seem to be on the increase. Could these things signal the opening of the Sixth Seal of Revelation? The biggest event to come out of the heavens will be the return of Jesus Christ on the Day of Trumpets.