Was I hit by a meteorite?
Between late August, and early September of 1996. I was hit in the left shoulder by,a falling star about the size of,a cigarette filter. When it hit , it felt like,a large horsefly flying into me.I reached, and grabbed it. It was a blackish gray rock with pitts in it. Then it decenergrated in my hand. Within less than an hour my shoulder started hurting, and I had burns on my finger tips. My question is. What was the weight of it,and how fast was it traveling, to hit me so hard that I did'nt feel the full effects of it until later? In case you're wondering the pain lasted about five days.
It's funny that you should send this in now, because I have just been reading up on the subject of meteorites hitting people for a class I'm a teaching assistant for! It turns out that recorded and undisputed events of meteorites hitting people are very rare! Take a look at Branch Meteorites for a list of meteorites which have hit objects/people. Many people will tell you that there is only one documented case of a human being hit by a meteorite. Other people will say that narrowing 'documented' to 'documented by a 20th century American journalist' is a little unfair. It's a bit controversial!
Meteorites enter the atmosphere very high up (right at the top in fact!) and by the time they reach the ground they are travelling at terminal velocity. Terminal velocity is basically how fast an object falls under the influence of gravity and air resistance, the actual speed increases with the size of the object so something the size of a cigarette filter would probably not be going much faster than a few 100 km/hr or so. When the object entered the atmosphere it would have been going much faster (on average meteorites enter at about 10-70 km/second), but air resistance (drag) slowed it to the terminal velocity as it fell. Most meteorites have sufficient time to cool as they fall at terminal velocity that they are not at all hot when they reach the ground. Some have even been reported to have frost on them! A common misconception about meteorites is that they could set your house on fire if they landed on them. This is not usually the case. Take a look at the site on "Bad Astronomy" which has an article about this.
Meteorites generally fall into two classes of types of rock. There are "Ordinary Chondrites" (which form the bulk of collected meteorites) which are generally grey and quite hard; the other type are called "Carbonaceous Chondrites." Carbonaceous chondrites are much blacker and more fragile and could easilly disintegrate in your hand.
Small meteorites which make it to the ground may have had much of their mass 'burnt off' in the first few moments of entering the atmosphere (as they slow to terminal velocity). I couldn't find out easilly how big a cigarette filter sized meteorite would have been on entering the atmosphere, but I would guess at least twice as big (or so) as it was on the ground (I would be glad of a correction if this is incorrect).
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