02-16-2013, 04:53 PM
Paul - difficult to say for certain but what you describe does sound like a meteor, or what's normally described as a fireball or bolide. The latter are meteors but instead of being a small speck of dust entering the atmosphere they are small rocks. They leave a trail and explode high up in the atmosphere due to ram pressure - this is what happened to the Russian meteor although in this case it was a few thousand tons of rock, not a small boulder! Essentially what happens is that the meteor compresses the atmosphere immediately in front of it causing the meteor to experience very high pressures, especially as the atmosphere gets thicker as it gets closer to the ground. At some point the pressure exceeds the structural strength of the meteor which breaks up violently. The energy released goes into the immediate atmosphere and surviving rock as heat hence the flash (and noise).
It's rare to actually hear these things, even big ones, but does happen. In this case the meteor broke up right above a city and because of its mass and velocity the energy released into the atmosphere (and windows in the streets below!) was the equivalent of a few hundred kilotons of TNT - several times larger than the atomic bombs dropped on Japan in WWII. The meteor exploded several miles above the city but a bang like that would clearly have been heard there. If you were a few miles away you might not have heard it although certainly would have seen it!
Fireballs/bolides happen all the time. They are spectacular when you see one (I've seen three or four in my lifetime) but usually are much smaller than the Russian one and you'd likely never hear the explosion, even if you were nearby. There are also cases where a rock skims the upper atmosphere. It gets in far enough to leave a trail which can go on for thousands of miles but then essentially bounces off the atmosphere and returns to space. I think there are a couple of videos of events like this on youtube. Will try and find them if you're interested. Pog might have even seen something like this. Pog - did it burn up, disappear or what? Am curious to know.
And nothing as exciting as that to show you from my dash cam, Pog! Sorry.
Tom
http://apacificview.blogspot.com/
It's rare to actually hear these things, even big ones, but does happen. In this case the meteor broke up right above a city and because of its mass and velocity the energy released into the atmosphere (and windows in the streets below!) was the equivalent of a few hundred kilotons of TNT - several times larger than the atomic bombs dropped on Japan in WWII. The meteor exploded several miles above the city but a bang like that would clearly have been heard there. If you were a few miles away you might not have heard it although certainly would have seen it!
Fireballs/bolides happen all the time. They are spectacular when you see one (I've seen three or four in my lifetime) but usually are much smaller than the Russian one and you'd likely never hear the explosion, even if you were nearby. There are also cases where a rock skims the upper atmosphere. It gets in far enough to leave a trail which can go on for thousands of miles but then essentially bounces off the atmosphere and returns to space. I think there are a couple of videos of events like this on youtube. Will try and find them if you're interested. Pog might have even seen something like this. Pog - did it burn up, disappear or what? Am curious to know.
And nothing as exciting as that to show you from my dash cam, Pog! Sorry.
Tom
http://apacificview.blogspot.com/