This can be an asteroid, but also a super-volcanic eruption as well, since it does say a great mountain burning with fire. Yellowstone, even the Great Syria-Africa Rift are areas that might erupt. Even in scripture, Christ sets his feet on the Mt of Olives and it divides in two. So a crack/fissure in the earth occurs. The area of the Dead Sea historically has been a hot thermal zone. The Syria-Africa Rift is 3500 miles long and has dozens of active and inactive volcanos along that rift. The area where Jesus was tempted, the demons sent into the pigs that were sent into the abyss happened in that area, the wilderness outside of Jerusalem. It is said,, demons dwell beneath the earth in this area and very likely, the angel that comes down and opens the Bottomless Pit is likely to happen in that area. Demon- locusts come out of this pit that smokes (like a burning furnace). But we can suspect that asteroids will be involved as well, since 1/3 of all ships are destroyed by the violent waves of the ocean. The Bible speaks of a worldwide earthquake which would also do the job as well. We will soon see ... or hopefully be taken out before that happens.