KFO

[PsychoSerenity]

Well, to you, even Oslo would be sparsely populated.

I think the important word here is "day time". You will not see The Flash in the day, unless you inhabit the DC Comics universe.

[mistermack]

I think the important word here is "day time". You will not see a flash in the day, unless the meteorite is huge.

What's huge?
The shooting stars we see at night are caused by tiny grains of dust, usually smaller than a grain of sand.
5 kg is huge, compared to that.
If it had sharp edges, indicating that it was part of a bigger one that exploded, then the big one was probably several metres in diameter, which would have definitely been noticed and heard.
That doesn't appear to have happened, so something looks wrong.

What's the smallest rock that can cause a flash that's visible in daylight? I dunno, I'd be guessing.
You can often see the Moon in daylight, and if a single grain of dust is bright enough to be clearly seen in the dark, I'd say that a 5kg rock could get easily shine more intensely than the Moon.

[MiM]

Quite a few answers to questions, that have come up here can be found here http://www.amsmeteors.org/fireballs/faqf/#3

If, I got it right, a meteorite likely to reach the surface of Earth would create a fireball, that could be visible in daylight, if far from the sun. Not necessarily visible if close to the sun.

[macdoc]

If it had sharp edges, indicating that it was part of a bigger one that exploded, then the big one was probably several metres in diameter, which would have definitely been noticed and heard.

Um several METERS......in diameter !!!!!!

I don't think so. There is no correlation to a stony bollide that big given the size of the rock observed.
http://fallingstar.com/historical.php

More like this

As for meteoroids big enough to form visible meteors, estimates for the minimum size vary. This is because there are factors other than size involved. Most notably, a meteoroid's entry speed affects its chances of reaching the surface, because it determines the amount of friction the meteoroid experiences. Typically, though, a meteoroid would have to be about the size of a marble for a portion of it to reach the Earth's surface. Smaller particles burn up in the atmosphere about 50 to 75 miles (80 to 120 kilometers) above the Earth.

About how much material is burned up?

Again, this depends on the speed of entry, the angle it comes in at (does it have time to slow down in the thin atmosphere?), and the strength of the material (fluffy comet material, rocky, or iron). It turns out that comet dust has a good chance of surviving. We find a lot of what are called "interplanetary dust particles" that make it to the surface of the Earth. This is because they are so small and light that they are slowed down very high in the atmosphere (50 to 100 km altitude). Really big objects barely notice the atmosphere and will make it to the surface. For fairly strong objects, good comparisons are: a VW bug outside the atmosphere will give you a microwave oven-sized meteorite or a basketball-sized object will give you a softball-sized meteorite.

<<<that

http://www.psi.edu/epo/faq/meteor.html

[mistermack]

Um several METERS......in diameter !!!!!!

I don't think so. There is no correlation to a stony bollide that big given the size of the rock observed.
http://fallingstar.com/historical.php

I was just going on what wikipedia says, which is fairly minimal :

Incoming objects larger than several meters (asteroids or comets) can explode in the air.

It's not really catagoric, it just left me with that impression that smaller objects don't explode, they just partly burn away.
If the object had sharp edges, going on that statement, it would have come from a very substantial rock that couldn't have been missed. But it might be wrong. It doesn't catagorically exclude smaller objects exploding, but that's what it seems to say.

[macdoc]

Why substantial??....many stony meteors are loose aglomerations of "stones' and any could have a fracture with water ice - heating in the atmosphere would fracture that with a simple steam explosion - no melting or ablation of rock required.
A fractured face does not imply the fracture occurred in the atmosphere....there's lots or opportunity in the solar system for rocks hitting each other.

[mistermack]

What they are saying is that if it has sharp edges, it must have broken up AFTER slowing down.

If a smaller rock has sharp edges, they will always get rounded off by the friction, and by melting, as it partially burns up on entry.
But if it's a big rock, it loses much of it's speed, then explodes into pieces, which don't get rounded off because they are travelling too slow by that time.

[Xamonas Chegwé]

Why substantial??....many stony meteors are loose aglomerations of "stones' and any could have a fracture with water ice - heating in the atmosphere would fracture that with a simple steam explosion - no melting or ablation of rock required.
A fractured face does not imply the fracture occurred in the atmosphere....there's lots or opportunity in the solar system for rocks hitting each other.

Yes. Sadly, rock on rock violence is on the increase in the Solar System. I blame Obama...

[mistermack]

Quite a few answers to questions, that have come up here can be found here http://www.amsmeteors.org/fireballs/faqf/#3

If, I got it right, a meteorite likely to reach the surface of Earth would create a fireball, that could be visible in daylight, if far from the sun. Not necessarily visible if close to the sun.

I just had another nose at that page you linked, and one bit stood out, showing just how unlikely this was to actually be a meteorite.

As an order of magnitude estimation, each square kilometer of the earth’s surface should collect 1 meteorite fall about once every 50,000 years, on the average.

If that's the frequency for a square kilometer, (a million square metres) then the frequency of one falling within a ten square meter patch is once every 5,000,000,000 years. ( five billion years ).

So that guy filmed a once-in-five billion year event for that location. I doubt it.

[PsychoSerenity]

Quite a few answers to questions, that have come up here can be found here http://www.amsmeteors.org/fireballs/faqf/#3

If, I got it right, a meteorite likely to reach the surface of Earth would create a fireball, that could be visible in daylight, if far from the sun. Not necessarily visible if close to the sun.

I just had another nose at that page you linked, and one bit stood out, showing just how unlikely this was to actually be a meteorite.

As an order of magnitude estimation, each square kilometer of the earth’s surface should collect 1 meteorite fall about once every 50,000 years, on the average.

If that's the frequency for a square kilometer, (a million square metres) then the frequency of one falling within a ten square meter patch is once every 5,000,000,000 years. ( five billion years ).

So that guy filmed a once-in-five billion year event for that location. I doubt it.

For that location yes. But that location has nothing special about it, - he just happened to be there. How many people these days are filming at other locations around the world right now? The odds are small, but I don't think they're small enough to write off the possibility.

[macdoc]

I think there is now a valid explanation for it being a rock from the the chute.

Quote:
Let’s get straight to the conclusion. The good news: The crowdsourcing was a success. The bad news: There is no meteorite. It was a rock accidentally packed into the parachute. But how? It was a scenario considered from the beginning and it kept haunting us until the time we went public, as Anders told in the TV interview. Despite much effort, we saw no way to reconcile this scenario with the videos. The rock was clearly falling from well above the parachute. It did not seem to accelerate as if released from the parachute. It fell several seconds after the parachute had fully deployed. So what did we miss? The riddle quickly cracked under the pressure of the numerous fresh eyes now looking at the problem. Several people were able to point out the important clue that made the pieces fall into place.

We think we can reconstruct what happened: A pebble, a few cm in size at most, was accidentally caught inside the parachute at the landing site after the previous jump. Then the parachute was packed on a clean floor and the pebble was not noticed. Then Anders made the jump with the stowaway. This is a wingsuit dive and he’s travelling fast northwards at an downward angle of approximately 40 degrees. When he releases the parachute, the wind catches it and it shoots out to the south of him. The parachute is held back by the cords, but the pebble is not. The pebble is now increasingly getting further south and further above Anders. However, the parachute then slows Anders down, he makes a 250 degree clockwise rotation and at this moment the pebble happens overtake him. It had now been falling for a few seconds and was no longer accelerating much.

http://norskmeteornettverk.no/wordpress/?p=1497

[mistermack]

If I was one of them, I'd feel pretty stupid not to have worked that out, before going public.

I suppose they deserve a bit of credit for discrediting their own claim. But only a tiny bit.
They didn't do it themselves, they just acted on what others were pointing out.

And if someone else had separately disproved it, they would have looked even dumber.

[PsychoSerenity]

It hasn't been disproved. The odds of a pebble doing what it did were pretty tiny too. It would have to be the right weight and be ejected from the parachute at the right speed and direction in order to fall past the parachutist later at high enough speed as to be indistinguishable from a falling meteor. The pebble explanation hasn't been disproved because it's been shown to be theoretically possible based on extensive calculations within the limits of the data they have, but that doesn't prove it's not a meteor. It was probably a pebble, but it's just a mater of relative probabilities.

[pErvinalia]

I think it was God.

[mistermack]

It hasn't been disproved. The odds of a pebble doing what it did were pretty tiny too. It would have to be the right weight and be ejected from the parachute at the right speed and direction in order to fall past the parachutist later at high enough speed as to be indistinguishable from a falling meteor. The pebble explanation hasn't been disproved because it's been shown to be theoretically possible based on extensive calculations within the limits of the data they have, but that doesn't prove it's not a meteor. It was probably a pebble, but it's just a mater of relative probabilities.

Fair enough, but I did say it's discredited, not disproved.
Given the astronomical (literally) odds against it being a meteorite, the pebble theory is the most likely, followed by a rock or pebble from the plane. Exactly as I said in my first post, on page one.

How do they know it was a meteorite?
I would firstly suspect something got wrapped up in the parachute. Then that something fell off the plane.
Meteorite would be if everything else had been disproved.

The meteorite theory would be millions of times less likely, in my estimation.