Timeline for Why do meteorites explode?
Current License: CC BY-SA 3.0
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 23, 2017 at 13:03 | comment | added | AtmosphericPrisonEscape | @SF: The comet hits with terminal velocity, the energy comes from falling down into a deep potential well, I hope that much is clear. After breakup the fragments are scattered through supersonic turbulence, which is a quite violent force, as one can see in the engineering efforts put into keeping airflow laminar at those lower mach-numbers for experimental planes. One uncontrolled maneuver can break your airplane apart, and that's at only Mach 2-3. Then of course the planes density is not that of solid rock. But to increase M by a factor of 10, increases energy dissipation by 100. | |
| Feb 23, 2017 at 9:49 | comment | added | SF. | @AtmosphericPrisonEscape: (sorry for necromancy, kinda missed the notification and forgot about this topic). This isn't "where I want to take that chemical energy from". This is about "where a suden energy capable of toppling multiple brick buildings in a wide radius comes from". Not from direct impact of meteorite fragments, or ground impact (the fragments were quite slow when reaching the ground) - and not from continuous energy release because the disatrous effect was instantaneous, not continuous. So...? | |
| May 3, 2016 at 13:07 | comment | added | AtmosphericPrisonEscape | @SF I don't know where you want to take all that chemical energy from, but a meteor sure doesn't have it. Also your violent spin will lead to piece-by-piece breakup and not a single, explosion-like event and that only for the icy-surface. In the case of the compact metal-rich meteors that we've been discussing here, no spin would break them apart. See the image uhoh attached. | |
| May 2, 2016 at 10:07 | comment | added | uhoh | @SF. Thanks for checking my math! Indeed 1 ton is 4.2 gigaJoules not 1 kiloton - my v was off by √1000. But I think "even if the meteor was made of 100% pure TNT (and not this stuff) and exploded, the energy released would still be only a few % of the kinetic energy dumped into the atmosphere" is ok. Still, if built-up heat & gradients -> sudden disintegration and you were moving along side and could see through the blindingly bright glowing atmosphere, it might look like a mild explosion. | |
| May 2, 2016 at 8:55 | comment | added | SF. | @uhoh I think you messed up your units somewhere. 1kg TNT = 4184000J = E = 0.5*1kg*v^2 ; v=sqrt(2*4184000) = 2893m/s. So 2.9km/s, not a measly 1 mach! | |
| May 2, 2016 at 8:43 | comment | added | SF. | @uhoh: at energies like these the border between explosions and any other processes really gets blurred. If you light a balloon filled with a few grams of oxygen and hydrogen mix, it explodes - so if you burn several hundred kilograms per second of that mix, it's hard not to call it a continuous explosion. And if the shockwave of a breaking meteor can seriously damage brick buildings, I somehow find any argument stating 'that's not an explosion' unconvincing. | |
| Apr 30, 2016 at 11:40 | comment | added | SF. | I'm completely sure that if a pretty solid (iron) meteorite is shaped in such a way that the air makes it enter a violent spin, the berak-up will be anything but gentle. But I have no clue how often this could occur. | |
| Apr 30, 2016 at 10:28 | comment | added | AtmosphericPrisonEscape | @rob: Imagine you travel on the comet. Then you are in its rest-frame. From this perspective an explosion would generate motion in all directions equally. This needs an energy source. However a break-up is just the comet loosing its structural support and then relatively gently falling to pieces. | |
| Apr 30, 2016 at 10:26 | comment | added | AtmosphericPrisonEscape | @SF: The meteor still hits pretty fast. That should account for all the damage. | |
| Apr 30, 2016 at 6:23 | comment | added | SF. | @rob: sometimes the break-up is quite non-violent. But in case of Chelyabinsk there was heavy damage to ground infrastructure, many wounded people - is that all result just of the (continuous, lengthy) shock front reaching the ground? | |
| Apr 29, 2016 at 22:26 | comment | added | rob | I'm a little murky on the distinction you make between "breaking up" and "exploding" --- you seem to be using these terms in a technical way that I'm not accustomed to. | |
| Apr 29, 2016 at 18:07 | history | answered | AtmosphericPrisonEscape | CC BY-SA 3.0 |
