What are the odds - Skydiver almost hit by meteorite

[Flyer10 31]

My wife was no more than a hundred feet from something that fell from the sky some years back.  She was walking along the beach.  I was some ways behind her.  The flaming object landed in the water.  From the bright green color, I would surmise that it was mostly copper and therefore a piece of space junk that de-orbited.

If that was me I would be like: "Just my luck! it missed her" :ph34r:

[january 19]

We need to see the original article.

 

Hope this helps-

http://www.nytimes.com/1996/09/19/opinion/l-in-twa-800-crash-don-t-discount-meteor-386081.html

Note that this calc refers to a period of 30 years- a 1 in 10 chance of collision over a 30 year period.

january

[LHookins 3,103]

Thanks, january.

 

So it's a 1 in 10 chance that at least one airliner has been lost to meteoric strike over the last 30 years.  Or, in round numbers, we can expect to lose an airliner in 300 years of air travel.

 

We've been sailing ships for a bit over that amount of time, and some of these ships have been quite large, although they average smaller than a modern large airliner.  How many ships have been lost to meteors?  Some would have only been damaged, not lost, so how many of these have there been?

 

Hook

[Matthew Kane 1,343]

I would say the odds are a large container ship is more likely to be hit by a meteor, then an airliner would be smaller, and a skydiver would be even more remote.

 

I am curious what are the number of Ocean Liners, Container Ships, etc that have been hit by a meteor, they have been around longer, much higher quantity of them, and much larger targets to hit. Even with that I have never heard of a ship that has been hit by one (Maybe there has been).

[january 19]

How many ships have been lost to meteors?

____________

My guess is "none".
 Meteoroids vs ships at sea level are not really comparable to airliners when it comes to extra terrestrial objects 

The small white hot rock at 40,000' has a velocity, temperature and mass (size/weight) vastly greater than the same object when it reaches sea level. 

 That is, it slows down quickly and erodes in size as it plunges through earth's denser, lower atmosphere.

I would expect the high velocity, super heated pebble that rips easily through thin aluminum at flight level, would also produce a very strong and destructive shock wave.

Below that level, the air density increases rapidly and the "rock" heats up further, erodes & disintegrates dramatically as it slows to terminal velocity. (about 120 mph.)

The former "rock" becomes a pebble or grains of sand when it strikes a ship. Additionally, the ship is built of 1/4 - 3/8" steel, so the captain may wonder what the bright light was in the sky last night, but only find a paint scratch on the bridge of his vessel!

january 

[Matthew Kane 1,343]

So  that means an A380 flying at 40,000 feet has better odds of being struck by a meteorite then anything on the surface as the meteor may still be large enough to cause a catastrophic event at that point, but continues to disintegrate as it descends into the lower atmosphere and to the surface. However, the odds of the two crossing paths are still extremely low (but could happen).

 

Never really thought about it before, Thanks January.

[Captain_Barfbag 31]

Depends on the size of the particle- always remember e=mc(squared) !

 

Well, not really.  Einstein's famous formula refers to the amount of energy which would be released if the matter were to be completely converted to energy, as in a nuclear reaction.  In a collision event, the relevant equation for kinetic energy would be:

 

                                             E_k = mv²/2

 

where m is the mass and v is the relative velocity of the two objects.  Even for jet planes and meteors, v << c, the speed of light.

[january 19]

released if the matter were to be completely converted to energy, as in a nuclear reaction.

 

Yes / agreed. Although a very high proportion of the meteoroid mass is converted to energy (light & heat) as it plunges into earth's atmosphere.

(Oh my- I'm reaching back into my High School physics classes of 65 years ago!)

january

[Captain_Barfbag 31]

 

 

Although a very high proportion of the meteoroid mass is converted to energy (light & heat) as it plunges into earth's atmosphere.

 

No, the mass is not converted to energy.  Instead, it combines with the atmosperic gasses in a chemical, not nuclear, reaction.  If you throw a log into a fire, the stuff that makes up the wood all ends up as carbon dioxide, water vapor and ash.  If you could do it, you would find that every atom of the wood was conserved, just rearranged in different molecular forms.

 

 

 

(Oh my- I'm reaching back into my High School physics classes of 65 years ago!)

 

My high school physics was only 49 years ago, so I do have the advantage of "newer science."

[january 19]

 

 

you would find that every atom of the wood was conserved, just rearranged in different molecular forms

Is the light and heat generated by a meteoroid plunging into earth's atmosphere, not energy?

january

PS Only two model railroaders would be likely to get into an esoteric discussion such as this !!!!!

january

[Matthew Kane 1,343]

Two physical objects striking really is irrelevant if the meteor was burning up at the time. Hot or cold the meteor would likely cause a catastrophic event on an aircraft.

 

Which leads me to believe that video is a hoax even more now due to the rock flying past appearing not to be heated.

[Captain_Barfbag 31]

Is the light and heat generated by a meteoroid plunging into earth's atmosphere, not energy?

 

Yes, but it is chemical energy from combustion, not nuclear energy from the annihilation of matter.

 

 

 

PS Only two model railroaders would be likely to get into an esoteric discussion such as this !!!!!

 

But any kind of engineers, locomotive or otherwise, will do this. I still remember taking a long hike in the woods where we discussed how gas refrigerators worked.  It was all very thermodynamic.

 

I model in HO scale, by the way, aiming for a dual-era layout where I can run steam in the 1930s or diesels in the 1960s, simply by replacing the engines, automobiles and most of the freight cars.

[january 19]

 

 

Which leads me to believe that video is a hoax even more now due to the rock flying past appearing not to be heated.

NASA planetary scientist Don Yeomans says "small rocky meteorites found immediately after landing will not be hot to the touch". That seems to be consistent with other reports from folks who have had them hit houses and cars etc

One might surmise that any high velocity heating from upper atmosphere entry, is lost after slowing and cooling in the final plunge through thicker air.

january

[Matthew Kane 1,343]

I used to model CN Rail in the 1950's in HO. Still have it in storage back in Canada and no way to ship it to New Zealand unfortunately. What I liked about it was the introduction of Diesel as I had some C-Liners as well as the Class K-3 4-6-2 steamers that CN ran from 1910 to 1961. I always liked to see a mix of Diesel and Steamers in the layout.

None of my trains have been struck be a meteorite  :lol:

 

NASA planetary scientist Don Yeomans says "small rocky meteorites found immediately after landing will not be hot to the touch". 

 

So there is a point where they cool off enough in the lower atmosphere.

[january 19]

 

 

None of my trains have been struck be a meteorite 

I was struck by a thought some time ago. Perhaps that's where I went off the rails!

january