German lad hit by 30,000 mph meteorite A 14-year-old German lad survived a close encounter with a meteorite when a pea-sized piece of rock which had entered Earth's atmosphere at 30,000 mph left him with nothing more than a "nasty" three-inch gash on his hand. According to the Telegraph, Gerrit Blank was on his way to school in Essen when a bright light in the sky …
How can a pea sized meteorite cause a "foot-wide crater in the ground" First up, the terminal velocity by the time its come through the atmosphere will be significantly less than 30,000mph, secondly its mass is going to be so small as to not have enough force to create a massive dint, even if its an extremely dense rock. If it were true, the southern United States would be covered in massive holes where bits of the shuttle Columbia returned to Earth. I don't doubt that this young fella got a whack on the bonce, but I suspect that it fell into a pot hole, and thats where the trouble started.
"Blank joins an exclusive club of meteorite-strike survivors,"
Only 2 survivors hey, exactly how many meteorite-stike fatalities have been recorded.
Should I be worried? Am I under threat? Will a tin foil hat help? Is the world at risk? Are we all going to die? Should I get the tabloid media to start a worldwide panic?
I don't understand how small, hot high speed rock, that can make a 1 foot crater in the ground, would 'bounce off' a boy's hand. I'd expect it to blast a hole in his hand and leave nasty burns. Similarly with the 3,86kg meteorite that 'bounced off' a radio. Can any meteorite experts help explain this?
Good news: You have the sort of luck that the one in umpty-something million chance comes up with your name on it.
Bad news: It involves being hit by a meteorite and 15 minutes of fame rather than being the sole winner of a quintuple rollover on the EuroMillions draw and a lifetime of sybaritic luxury.
And of course anybody who's seen The Andromeda Strain is now waiting for Gerrit to fall over dead having been dessicated from the inside by a space-borne superbug...
Followed by the rest of Essen, Germany, Europe and eventually the World, unless we can get him to Wildfire a.s.a.p....
Small meteorites shed almost all their velocity in the upper atmosphere and hit the ground at only a few hundred kilometres an hour maximum - enough to give a nasty whack, but not enough to excite Michael Bay.
And as for the red hot bit - sorry, witness evidence suggests that meteorites are rarely more than warm when they arrive. They've been sitting in the cold of deep space for the last few billion years. The meteorite is protected from the frictional heat by the ablation of the outer layer, so relatively little heat gets to penetrate the rock itself. One scientist who picked up a fresh meteorite compared its temperature to a baked potato - too hot to hold, but not so hot that it would cause a serious burn.
Still, hit by a meteorite eh? That's a good excuse for skipping PE!
b*llshit.
On the back of a fagpack...Anything with any substantive mass travelling at this speed would go straight through a human hand. A hign speed bullet roughly equates to 3,500 mph at max velocity. Bullets don't bounce off human hands at peak velocity.
So mass andaerodynamics wise, how many stone peas equate to a bullet. Hmmmm I guess possibly more than 9 peas so I retract, this might be possible. Move along, nothing to see here!
Anyway, either very lucky or those german experimants in the 40's.....
Maybe in the vacuum of space but not once it was at ground level. If it was doing 30,000 at sea level it would be an incandescent ball of plasma and there'd be nothing left of the boy or probably his school!
And can someone tell me what his hand is made of if it "bounced" off it yet still made a foot wide crater in the ground? Is the boys name name C. Kent by any chance?
Good old Torygraph, you can always guarantee their scientific reporting is about as accurate as a broken clock.
Let's see now. A pea sized meteorite would be around 6mm in diameter, and assuming it's a typical chondrite, will have a density of around ~3.4g/cm^3. Its mass would be around 0.4 grams.
At 30,000 mph, it would have a kinetic energy of 36kJ. Compare this with the kinetic energy of a round fired from a P90, around 520J.
Just a gash on his hand?!?
I suspect its velocity was somewhat less than quoted.
Surely it should be more like 71%, or roughly 5 out of every 7 - given that this proportion of the earth's surface is water ? What is it about meteorites that make them preferentially target water ? Is it something to do with meteorites being more likely to hit in the mid-latitudes where the ratio of water may be higher ?
So, this thing was fast enough to dig a rather decent hole into the ground but faild to obliterate Mr Blank?
Interesting.
Fortunately I live in Essen, so I´ll keep you posted...
*clicketyclack*
http://www.derwesten.de/nachrichten/staedte/essen/2009/6/10/news-122286237/detail.html
ok, no hit, just a close miss.
"bounced off his hand"
Really? Bounced? Somehow the connotation of bounce doesn't lend itself to be followed by "embedding itself in a foot-wide crater in the ground." Granted it's small, I assume your peas are the same as ours being about the size of #4 buckshot (6 mm), but an energy exchange great enough to make a crater was certainly not done after bouncing off anything. That isn't to say it didn't go through the lad's skin, it just means it didn't transfer much energy as it did. If he had a bit more luck it would have cauterized the wound on its way through.
The BBC website offers the fascinating information that "the chances of being hit by a meteorite are 1 in 100 million". By that reckoning, over 60 people are about to be hit by meteorites.
Chances in what time-frame, anyway? The chances of being hit in a year are obviously 365 times the chance of being hit in a day.
This is the quality of reporting that brought you "bounced off his hand". I wouldn't rely on it in court.
Thumb indicates direction of travel.
@ CAD MONKEY
Terminal velocity for a human in a typical arms and feet out pose is ~ 120 mph. In a nose dive a human can exceed 200 mph. Last I checked a pea was a brave bit smaller than a human...
The terminal velocity for a pea sized rock is -
Vt=(0.2222*g*(dm-da)*(r^2)/n
where * stands for multiplication, / stands for division
g is the acceleration of gravity (~980 cm/s^2)
dm is the density of the meteorite (~2.7-3 g/cm^3 for rock)
da is the density of air (~ 0.0012923 g/cm^3)
r is the radius (half the diameter) of the metorite in cm
n is the dynamic viscosity of air near the Earth's surface (~ 0.00018 g/cm/s).
thus the terminal velocity for a 0.3 cm meteorite with a density similar to granite is ~ 1800 mph.
What speed it was actually doing is another matter, but it could have potentially been zipping along ;)
Seems eminently plausible. To say it "bounced off" his hand is clearly bad wording, but it could easily be a glancing strike which just takes out a gouge. And while it would have been doing less than 30,000 mph by the time it reached earth, it would still be going bloody fast and have enough energy to make a small crater. Photos at http://www.derwesten.de/nachrichten/staedte/essen/2009/6/9/news-122286237/detail.html
I love how most people say he's lucky. As if it's lucky to be one of only a handful of people to get hit by a space rock. I would normally call that unlucky in the extreme. It's like when Uncle Ernie ties one on and wraps his pickup truck around a tree, loses a leg and his spleen but survives and people call him "lucky".
However, if he was actually hit by it, he is extremely lucky because apparently the demand for meteorites that hit man made objects (and surely he must qualify) is HUGE and the kid could earn quite a nice wad of cash for his pain.
But as with other writers, I am in severe doubt of the entire story given this 2 foot crater nonsense.
Depending on the angle it hit the atmosphere, it may only have been in the atmosphere for a handful of seconds before striking the ground. The upper atmosphere is significantly less dense than the lower atmosphere as pressure decrease is not linear with height increase.
It would have experienced aerobraking and shed some of it's momentum as heat and light due to friction, which would have made it pretty hot, and would most likely have struck the ground travelling significantly faster than terminal velocity. The real question is why only a single piece has been recovered when one would expect anything striking tarmac that hard to shatter.
@Colin 4 - Most matter in the solar system tends to orbit the sun on or near the ecliptic plane, which is at an angle of 23.5 degrees from our equator, so one would expect the majority of meteorites to hit the Earth in this region.
"... a pea-sized piece of rock which had entered Earth's atmosphere at 30,000 mph"
Hmm. So no info on what speed it was actually doing when it hit him.
"It bounced off his hand before embedding itself in a foot-wide crater in the ground."
But it doesn't say that the space-pea made the crater. Just that it landed in it and got stuck.
So the entire article is summed up with, "Boy hit by pea-sized meteor gets cut hand". Nothing to see here, folks. Move along.
Cheers
Peter
--- each of those trying to show how clever they are by commenting on the implausibility of the story, and on the 30,000mph figure. Clearly they didn't read the article which states that the meteorite "had entered Earth's atmosphere at 30,000 mph" not that it was traveling at 30,000mph when it hit the youth. As to the rest of it, yes it's a a rare event, clearly the odds of a human being having that experience are less than one in 100 billion since as far as we know it is unique.
http://www.derwesten.de/nachrichten/staedte/essen/2009/6/9/news-122286237/detail.html
The "crater" in the newspaper photograph does not look like a crater to me - and I certainly feel that the "crater" was not caused by the meteorite.
Another rubbish newspaper story. However, the story has distracted enough of the readership of El Reg for a full Earth Invasion fleet to have arrived without anyone noticing.
I'm not quite sure about how much the atmosphere would have slowed down this pellet but here are some thoughts.
1. In reference to people making guesses as to the speed of impact and judging the crater size to be implausible. It may be that the way the speed was estimated was to measure the mass of the meteorite and the size of the crater and use a relevant algorithm.
2. As our victim heard a loud bang after, but not before, it sounds like the meteorite was traveling at least the speed of sound.
3. I would tend to agree that if this object hit any part of him at such a high speed, then the body part would no longer be a part of him. Perhaps he is mistaken and the object went very close to him. If it was traveling at some hypersonic speed then the shock wave or heated air around the object could plausibly have caused his injury. Also craters throw up a huge amount of material when they are formed (1 foot wide hemisphere of dirt in this case). Some lower speed material ejected from the crater could plausibly have caused his injury while also chucking him a fair distance away. If the object was traveling at 30,000 mph, there's no way he could have resolved the time difference between the injury to his hand and the object hitting the ground.
The size of the object had nothing to do with him being lucky! Have you seen the size of a bullet slug recently? They're not much bigger, travel a hell of a lot slower and they kill people.
I recommend reading up on a couple of things called kinetic energy and momentum (assuming basics physics is still taught in our science deprived society).
With that kind of velocity it would have carried so much energy it would have made Dirty Harry blush, and blown his head clean off had it hit him directly. Actually it would probably have just gone straight through it without so much as batting a rocky eyelid. The effect to the kid would have been the same though.
The fact that it exploded leaving a crater in the ground gives you an idea of the energy.
So it didn't "bounce" off his head, it skimmed his head and continued the same direction it had been going... In fact at that speed it could have been the shock wave that damaged his bonce and the object didn't actually touch him.
thank you Steve ... for pointing out the most obvious answer ... it could have easily 'skimmed his hand' as steve said and continued into the ground. Hasn't anybody ever gotten grazed by a bullet?
even when getting hit by a bullet, not every shot causes a huge hole on the exit wound. you usually need hollow point bullets. it's possible the meteorite would have just gone straight through the and left a hole it's exact size. as someone said 'knife through butter'
Looking at the photos at http://www.derwesten.de/nachrichten/staedte/essen/2009/6/9/news-122286237/detail.html I would say the injury to the lads hand is more like a burn. I think the meteorite, still hot due to its high velocity passed close enough to Mr Blank's hand to cause a burn.
The crater doesn't look much like a crater to me, though there appears to be evidence of heat damage to the tarmac. I am waiting for our local council to start blaming all the potholes in our disgraceful (and dangerous) roads on meteorite strikes, rather than ineffective maintenance programs !
If that thing had really hit Mr Blank, I think he would have a nice neat hole through him. Even if the meteorite had shattered the sheer velocity would have meant the fragments passed through in a closely grouped cluster. The shockwaves to internal organs would have been pretty bad though. Contrast this with a dum dum bullet : low velocity and soft. This means it easily spreads out on impact, and the low velocity guarantees plenty of time to do so. The result is a very nasty wound, a small hole at entry, and a large one at exit.
Mr Blank is a very lucky young man. I hope he can keep the meteorite to show the girls ...
Ok, I've got it.
It grazed his hand, then mid-flight, changed direction, twice, sped up, then hit the ground with suitable force to create a one-foot crater. From the barrel marks on the meteorite, it appears it is actually the very same magic bullet that hit Kennedy.
Wow. If you think there's "nothing to see" in someone actually getting hit by a meteorite, you must lead a really interesting life. But then you're here, so I'll just put it down to either films or computer games desensitising you. Or are you just one of those sad 'Im so jaded, seen it all before ' poseurs who like that irritating catchphrase?
At 30,000 mph (or whatever speed it was traveling at once at ground level) I doubt one could tell what the sequence events were. It hits hand, then craters the ground? We're talking on the order of microseconds difference.
I'd say it hit the ground and his hand was probably struck by the ejecta from the crater produced.
Small correction. Terminal Velocity is not some sort of absolute "light speed" of matter. It is the final (hence 'terminal') equilibrium between drag and gravity that eventually arises. So when jumping out of a plane, you will go faster and faster until you reach this speed, but something dropping in at 30Kmph will on the other hand slow down until it reaches this speed. Unless it is going so fast that it hits the earth before being slowed down to it's terminal velocity of course, as is probably the case here.
Btw, an interesting rule of thumb: above 2 km/sec, an impact of x mass is equivalent of that mass in TNT. This equivalent amount is squared that of any additional increase. So 1 kilo of rock at 2 Km/sec = 1 kilo of TNT, but one kilo of rock at 16 km/sec = 64 kilos of TNT, and so on.
Technically, you are correct on both points - that Ann Elizabeth Hodges was also struck by a meteorite and survived (until she died 18 years later), and that as a survivor of a meteor strike he is a member of an exclusive club with a membership of two - however the only other member (as Ms Hodges ceased surviving 37 years ago) is a Ugandan who was struck but not injured in 1992 and can reasonably br assumed to still be alive.
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