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Collided Satellite Debris Coming Down?
Jamie found this Bad Astronomy blog on the many reports beginning about 7 hours ago of one or more fireballs in the sky across Texas. That blog's proprietor first doubted that the phenomena could be due to the satellites that collided in orbit last week, but later left the possibility open. The National Weather Service for Jackson, KY put out an announcement about possible explosions and earthquakes across the area and blamed the defunct satellites. "These pieces of debris have been causing sonic booms...resulting in the vibrations being felt by some residents...as well as flashes of light across the sky. The cloud of debris is likely the result of the recent in orbit collision of two satellites on Tuesday...February 10th when Kosmos 2251 crashed into Iridium 33."
An Austin TV station has more reports.
From a few tons of colliding satellite? Seriously?
Oh dear, someone doesn't have a well tuned sense of scale methinks.
A learning experience is one of those things that say, 'You know that thing you just did? Don't do that.' - D. Adams
This is obviously true, but it usually takes a while for debris to de-orbit especially if it's not in very low orbit (where it will encounter more atmospheric drag). Offhand the only way I see for this to be likely to happen so quickly would be if the satellites had been moving in opposite directions (a head-on collision, in other words) - that ought to result in at least some debris having a markedly different orbital energy from that of either of the two satellites before the collision. But most satellites orbit in either an easterly direction (it takes less energy to launch them in that direction because you get an energy boost from the Earth's rotation) or in a polar orbit (which is useful because even though it requires more energy the satellite can pass over all of the Earth's surface) - so head-on collisions are relatively unlikely.
He's a troll because he wrote a first post sensible and intelligent!
Well, sure, if you're lobbing satellite parts at the moon. The earth has an atmosphere, though. Air resistance doesn't scale linearly. The faster your initial velocity, the greater your loss of velocity due to air resistance. At very high velocities, air resistance increases exponentially. Therefore, double the velocity on de-orbit does not mean double the impact velocity.
A low enough mass won't impact at all - it'll burn up long before it hits the ground.
It might make an impressive impact. Without knowing the variables, you have no basis for concluding that it would.
He's marked Troll because of how stupid it is to worry about someone getting hurt from this. Or do you worry that every time you exhale it could cause a storm somewhere that kills someone?
There might well be a few fragments of several kilograms, but the fragments most likely to have a sufficient change in momentum to be able to deorbit that quickly could hardly be very large: The total sum of the momentum of all of the pieces before and after the event needs to remain constant; most of that debris is still going to be traveling at orbital velocities.
This event was visible in broad daylight, at 11:00 in the morning. Whatever it was, it must have been a pretty good-sized object.