PSA: meteors have nothing to do with explosions. The shockwave comes from meteor's movement alone, the parts never move apart with any speed comparable to their common forward motion.

A breakup will increase surface area and therefore kinetic energy to shockwave transfer efficiency, still not an explosion.

▲

margalabargala 6 hours ago | parent | next [-]

PSA: The word "explosion" has multiple definitions, plenty of which are actually quite reasonable to apply to meteors! It can refer to the sound alone, for example. The people reporting an explosion in Massachusetts were not incorrect!

It would however, be incorrect to claim that the meteor had noting to do with explosions.

▲

jagged-chisel 6 hours ago | parent | next [-]

None of the definitions I found are concerned with only sound. One mentions sound as a result of an explosion.

PSA: expressing an opinion (incorrect or otherwise) is not actually a public service announcement

▲

jojobas 6 hours ago | parent | prev [-]

No? There is no violent expansion or bursting, even if the sound is similar. It is as much an explosion as a supersonic jet passing by, and that is not much.

The term makes people think atmospheric heating causes an actual steam explosion and that's the source of shockwave, which can't be further from truth.

▲

sholladay 3 hours ago | parent [-]

Do you not consider Tunguska an explosion? It’s always described as such. IIRC, it never even hit the ground. Sure, a lot of the damage was caused by the air being compressed from above, but it created an air burst, which would have released a lot of energy in every direction.

	▲	jojobas 3 hours ago \| parent [-]
		No, it's a misnomer as with any other meteor. If you were to witness the breakup from the bolide's reference frame and without all the rushing air you'd never call it an explosion.

▲

1970-01-01 4 hours ago | parent | prev | next [-]

>The shockwave comes from meteor's movement alone, the parts never move apart with any speed comparable to their common forward motion..

PSA is false.

https://www.nasa.gov/blogs/watch-the-skies/2026/03/26/its-fi...

▲

dredmorbius 4 hours ago | parent [-]

jojobas and NASA's statements aren't contradictory.

NASA states: "the fragmentation of the fireball unleashes large amounts of energy, which also generates a pressure wave that can produce a very loud boom, even shaking houses."

Fragmentation of a fireball, whilst not explosive itself (the particles needn't diverge at a supersonic relative velocity) are nonetheless part of a supersonic / hypersonic particle field relative to the atmosphere they are passing through. Expanding the diameter of that particle field will increase the size of the resultant shockwave, whether the particle separation itself is "explosive" or not.

The "explosion" then is of the deceleration (aerobraking) shockwave, not the bolide separation. But the bolide separation increases the intensity of the shockwave, with more (and lighter) particles interacting with the atmosphere over a shorter distance than an intact, small-diameter bolide would.

Some of this depends on what definition of "explosion" one chooses, or whether people are intending an explosion specifically, or an explosive sound (sonic boom). That's confounded by bolide separation, the bright light emitted on entry, and sonic effects, all of which are semantically associated with other explosive events. Language is a consensus phenomenon.

I'd tend to call the event an explosion, though not in the expanding particle field sense.

▲

1970-01-01 3 hours ago | parent [-]

Your statement is not supported by, and is somewhat at odds with, physics. As described in this source, observed terminal brightening/"burst" of a bolide is tied to the body's material behavior (fragmentation, rapid lateral expansion, ablation), and not to a free-standing "deceleration shockwave" that exists independently of the body breaking up.

https://adsabs.harvard.edu/full/2001ESASP.495..491R

	▲	dredmorbius 2 hours ago \| parent [-]
		You're being excessively argumentative. I didn't state that the shockwave is independent of whether or not the body breaks up, I wrote, emphasised, "Expanding the diameter of that particle field will increase the size of the resultant shockwave, whether the particle separation itself is "explosive" or not." Which your article (partially read, sorry, incredibly shitty reader) largely substantiates, largely in the itemised list in section 2.2. Pancaking of a bolide through fragmentation increases frontal area, has multiple points of mass interacting with the atmosphere over a larger area and with less mass at each point, and the (undiscussed) light-emission mechanism which itself largely derives from compressive heating and ionisation of the atmosphere (rather than friction against the atmosphere or heating of bolide particles themselves). Increasing the number, and surface areas, of particles increases the region and intensity of this effect. As your source discusses, most fragmentation is a result of mechanical rather than thermal forcing of the bolide.

▲

quuxplusone 5 hours ago | parent | prev | next [-]

The Wikipedia article on "meteor air burst" has an explanation that basically matches yours, although they do use the word "explosion" to describe it. Which makes sense to me: whatever one chooses to call it, it's a nearly instantaneous spontaneous disassembly that is very bright, very hot, and very loud.

https://en.wikipedia.org/wiki/Meteor_air_burst

	▲	jojobas 5 hours ago \| parent \| next [-]
		The speed scale for disassembly is nowhere near the forward speed; you never get anywhere close to 45 degree debris divergence angle. It's also, again, not the disassembly that causes it to be bright, hot and loud. Wikipedians can also be wrong.
	▲	gruntled-worker 5 hours ago \| parent \| prev [-]
		We are not disassembling, we are assembling in another time direction.

▲

Guestmodinfo 3 hours ago | parent | prev | next [-]

You are correct in class 9 physics book in India we have a mention of supersonic planes producing a sonic "boom" so the suprsonic planes don't themselves explode but their fast movement makes the air produce the boom. So you were correct as far as I can tell. But meteors do get smaller and smaller due to extreme friction from air and they do break into several pieces so that can also add to the sound.

▲

Jblx2 6 hours ago | parent | prev [-]

https://www.dictionary.com/browse/explosion