Small meteor impact last week in Greenland.

Post Reply New Topic

There was a small meteor impact in Greenland last week on 25 July. It produced an explosion equivalent to around 2,100 tons of TNT. This describes the event. A BRIGHT METEOR OVER GREENLAND DIDN'T SPARK NUCLEAR WAR. [PHEW]

The video in the article is interesting to watch.

2100 tons of TNT?

That's a lot.

One seventh the power of the Hiroshima bomb (14 kilotons).

The weight of a general purpose airforce gravity bomb is about fifty percent actual explosive. So its equivalent to 4200 tons of bombs, or the payload of about 28 B 52s,

Anything that strikes the earth from deep space is going to be moving at at least the same speed that the earth itself is moving in its orbit around the sun (like 40 thousand miles an hour). Even small rocks pack a whallop when they move at that speed.

So what about all the radiation coming from this meteor? Is it going to melt the ice caps and poison everyone even remotely near it, or will the cancer rate just quadruple?

In general asteroid impacts do not produce radioactive materials like in a nuclear weapon fallout. This is such a small impactor, the effect is minimal. Impacts happen all the time. But it is the big ones that you might need to be worried about.

I don't see why there would be any "radiation".

Just because it makes a big bang doesn't mean it produces "radiation".

Radiation is the by product of nuclear fission. Not of big explosions.

Man made atomic bombs produce radiation because those devices get their explosive power from nuclear fission.

A stick of dynamite the size of the Washington Monument might be as powerful as the Hiroshima bomb, but it wouldn't produce any radiation the way that the Hiroshima bomb did because its a chemical reaction, and not a nuclear reaction.

A natural meteor like this is equivalent to neither a nuclear bomb, nor to a conventional chemical explosive, but is a natural "kinetic energy projectile" (like a bullet, an old fashioned solid-shot cannonball, or the shells fired by the modern M1 tank). The destruction is the result a simple mass combined with huge speed (like two cars crashing head on).

WHAT radiation? Have you been watching too many black-and-white science-fiction movies from the 1950s?

Any release of radiation is minimal. But for the purist I cannot say NONE, there is a very small amount.

Are meteorites radioactive?
Again the answer is not a simple yes or no. They are not radioactive as a piece of uranium ore or even a smoke detector for your home is radioactive. But, freshly fallen meteorites do release activity from very short lived isotopes that scientists are very interested in. The sooner a stone can get to the laboratory for study the better these weak reactions do not last long and can only be detected in a lab. They pose no danger at all.
Meteorite Facts

a while back I watched a meteor disintegrate in mid-air in a large fireball display, surprisingly it made not a sound [don't know how distant it was] but I wondered how large it was.

According to the article the meteor exploded around 40 or greater kilometers above the surface of the earth. That is around 25 miles from the surface of the planet directly below where it exploded. So if the meteor explosion that you saw was similar, you were probably look at the event from an angle. So it is quite conceivable that the explosion may have been 50 miles away. That may be why you did not detect the sound of the explosion for the one you observed. Or the one you observed may have been a smaller impactor.

the one I saw was northeast of me which would have put it somewhere between me and the Canadian border. there were no reports about it. I later read that multiple witnesses saw another one crashing into the northern pacific ocean, which is about 70 miles distant from me, as the crow flies. so at least that one could not have been too big or else there would have been noted violent wave activity which was never reported.

Cool thing to see!

Something that exploded 25 miles up, and above a point (say) fifty miles away is gonna be like 125 miles away from you. So it would take sound about ten minutes to reach you. You would see the explosion, but not hear it for another ten minutes. You might have heard sumpin like thunder minutes later, and not thought to connect the sound in your mind to what you saw.

if there was thunder it was masked by local wind noise. I generally stay outside about 20 minutes or so, stargazing in the cooler evening air, until the twilight fades to darkness.

Exactly.

A rock the size of car disintegrating might not have even have made a sound. If it did actually "explode" (even if it happened on the ground) the sound would be weak by the time it reaches an observer dozens of miles away. And that weak sound could easily be masked by local noise.