^6:12 And I looked when He broke the sixth seal, and there was a great earthquake; and the sun became black as sackcloth made of hair, and the whole moon became like blood;

And I looked when He broke the sixth seal, and

• there was a GREAT EARTHQUAKE, and
• the SUN became BLACK as sackcloth made of hair, and
• the whole MOON became like BLOOD; and

These three things along with the next two verses appear to be all one event. It may be that a great impact from outer space will cause the earth (all of it) to shake so violently that volcanoes erupt everywhere spewing ash throughout the atmosphere. This would darken the sun and at night make the moon appear blood red.

When God moves to "talk" to people, these types of natural phenomena appear (Exodus 19:16-25). Also note that repentance and consecration are required before entering the presence of God.

The Old Testament prophets also saw, in visions and dreams, similar events. Jesus refers to the signs to take place in the sun, moon, and stars. Here are a few references:

• Joel 2:1-11
• Joel 2:28-32
• Isaiah 2:12-22
• Isaiah 13:9-13
• Jeremiah 4:27-31
• Ezekiel 32:1-8
• Zephaniah 1:14-18
• Matthew 24:29-31
• Luke 21:9-11
• Luke 21:25-28
• Mark 13:6-8