Do meteors explode?

[pendell]

Seen in Universe Today

A meteor that exploded in the air near the Dead Sea 3,700 years ago may have wiped out communities, killed tens of thousands of people, and provided the kernel of truth to an old Bible story. The area is in modern-day Jordan, in a 25 km wide circular plain called Middle Ghor. Most of the evidence for this event comes from archaeological evidence excavated at the Bronze Age city of Tall el-Hammam located in that area, which some scholars say is the city of Sodom from the Bible.


Archaeologists have been digging at the Tall el-Hamman site for 13 years, and have unearthed some pretty convincing evidence supporting the air-burst idea. The findings were presented on November 15th at the annual meeting of the American Schools of Oriental Research, by archaeologist Phillip Silvia of Trinity Southwest University. They were also published in a paper by Silvia and co-author and archaeologist Steven Collins called “The Civilization-Ending 3.7KYrBP Event: Archaeological Data, Sample Analyses, and Biblical Implications”.

There's something that bothers me about this.

How exactly does a meteor "explode"?

I can imagine a meteor coming apart into a shower when entering the atmosphere, and I can imagine a rain of meteorites resulting from that, but I have absolutely no idea how a meteor would "explode". Your typical meteor isn't made of explosive material.

So ... any idea what they're talking about, or are the archaeologists well out of their field of expertise?

For that matter, I can think of very few instances where we have examples of meteor showers hitting for major impacts. Meteors that really make a mark, like Tunguska, usually come down in one piece.

So my question: Does this make any sense from an astrophysical point of view?
Respectfully,

Brian P.

[Tvtyrant]

Meteor comes in at too steep of an approach angle and too fast, it compresses the air beneath it until the air molecules can't get out if the way anymore. This super heats the air and makes it act like a wall, shattering or even repulsing the rock and creating a shockwave as the superheated air seeks to escape.

I'm reasonably certain that is the correct explanation and accounts for the big sky explosions that break people's windows a hundred miles away.

[halfeye]

Sometimes, yes:

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

That one was fairly recent. I don't think we know enough about the Tunguska explosion to say exactly what caused it.

[Razade]

That one was fairly recent. I don't think we know enough about the Tunguska explosion to say exactly what caused it.

Not with anything approaching definitive but most theories that aren't psuedosience and woo...suggest it was a meteor or at least something similar.

[pendell]

Meteor comes in at too steep of an approach angle and too fast, it compresses the air beneath it until the air molecules can't get out if the way anymore. This super heats the air and makes it act like a wall, shattering or even repulsing the rock and creating a shockwave as the superheated air seeks to escape.

I'm reasonably certain that is the correct explanation and accounts for the big sky explosions that break people's windows a hundred miles away.

That certainly sounds reasonable. In the absence of additional information I accept this as an explanation as to why meteors can explode and why the theory is therefore prima facie plausible.

Respectfully,

Brian P.

[Mechalich]

Meteors are not necessarily solid. During atmospheric entry, air is forced into cracks and gaps in the structure of the meteor, meaning that high-pressure air is streaming through the internal structure of the meteor. This, combined with the pressure gradient moving across the meteor as a whole - because air is compressed in front but a near-vacuum in back, introduces massive internal stresses and causes the meteor to blow apart. This is actually rather similar to how a steam pipe explosion happens.

[Tvtyrant]

I found an article on the Tunguska event. http://www.igpp.ucla.edu/public/mkiv...20Tunguska.pdf

[Rogar Demonblud]

The variegated nature of meteorites also mean that they can have components that will heat at differing rates, plus there are some compounds that can ignite if they get hot enough put which won't sublimate away in space vacuum (pretty much anything CHON related).

[Lord Torath]

Here is a very relevant Bad Astronomy column: Why Do Asteroids Explode High in the Atmosphere?

[tomandtish]

The variegated nature of meteorites also mean that they can have components that will heat at differing rates, plus there are some compounds that can ignite if they get hot enough put which won't sublimate away in space vacuum (pretty much anything CHON related).

Very true. This same thing is the reason why Mythbusters proved that jaw breakers can explode under the right circumstances.

[Tvtyrant]

Here is a very relevant Bad Astronomy column: Why Do Asteroids Explode High in the Atmosphere?

Neat! It says the explanation I gave is true but incomplete, since then scientists have moved to Mechalich's explanation.

[shawnhcorey]

One possibility is the heat from entering the atmosphere causes the water in them to flash over to super-heated steam and causing a steam explosion.