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Pennsylvania Meteor Report

squiggy writes: "Turns out the scorched corn field in Pennsylvania, and the reports of car sized space rocks hitting the earth were a bit overthe top. Likely, the object was very small, disintegrated before impact, and anything that might have reached the ground intact would have been cold to the touch. The full story is here"

27 of 82 comments (clear)

  1. The county would never have noticed by maggard · · Score: 2
    OK - figger this thing was a coupla thousand pounds entering the atmosphere, likely well (!!!) under 2000 pounds total (remember it broke up) when it hit the ground if it did come down in discernable parts. Truth be told it was probably a few pounds total on the ground but we'll be generous.

    No take a look at the speed - I don't actually know what the terminal velocity of of rock is but I'm guessing 150-300 MPH. Sounds impressive 'till you realize that there are cars that can hit the low end of that. It's fast but we're talking terrestrial-fast, not astronomical-fast.

    So, now figger what damage a sports car going very very fast would do to the county: Not much. Seriously - a sports car weighs around a thousand pounds or so, what would one do if it hit a particularly hard part of the county - say slamming into a cliff along the highway?

    Oh, the neighbors might hear the impact or notice the new ditch next door but we're not talking plowing-up-the-earth walls-of-flame call-out-the-Nat'l-Guard stuff here. It's a thud & likely a good thud but still a thud.

    Even doubling the speed of the car doesn't do all that much - you just get a stronger thud that would rattle the dishes & crack some plaster on houses close by but that's about it. Now make it a car that's solid all of the way though - still just a big thud. Folks a few blocks away might hear & feel it but still not going to rattle any seismographs in the next state, probably not even ruin any houses it doesn't actually hit up against.

    For comparison btw recall that a similar meteor behaved about the same of northern Canada last year and how many parts from it were found on the surface of a frozen lake. Not punched-though but laying on top of the ice melting through slowly - from solar-heat (like any rock on a frozen lake.) Not glowing hot, not punching through the ice, just sitting there.

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    1. Re:The county would never have noticed by maggard · · Score: 2

      We're talking a couple thousand pounds; aerodynamic forces are going to overwhelm any initial velocities this thing has. If we were talking a small mountain then yeah, the atmosphere wouldn't be so much of an issue but in this scale its the largest factor. Meteors don't come in at that great a velocity (and ok I'm cheating - I used to teach this stuff.)

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      I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
    2. Re:The county would never have noticed by maggard · · Score: 2
      Yes darling - it would start out big.

      In this case possibly up to a coupla meters. However a cold rock dropped into an atmosphere with a extremely hot pressure gradient ahead of it ablates pretty fast, by the time it comes down to ground level we're talking a total mass of possibly a few tons and likely distributed amongst several objects. For numbers it's gonna hit the atmosphere at 10-70 km/second, at the bottom will be going a couple hundred kph, the same speed as if it had been dropped from a tall building.

      You're right if it's city-block size or greater; it's gonna come down, come down hard & our atmosphere ain't gonna do much for us. But for things much smaller life is a lot rougher for them, better for us. For something under 50m the majority of it will burn up in the atmosphere & the local effects will be minimal.

      For some more numbers a 3m diameter object of meteoric metals (x3.5 mass of generic terrestrial rock, a stony (chondrite) would be x1.5) could weigh up to 100 tons and upon impact would create a crater 3 - 5m in diameter. It's kinetic energy is the product of the mass and the square of the velocity. Impressive, but not hazardous outside of it's immediate vicinity & certianly of no danger to the county*.

      Finally here's a MPEG of a stony coming in through the atmosphere & hitting a parked car in Peekskill NY on Oct. 9, 1992 - it was 12Kg when recovered.

      * For non-US readers a "County" is a subsection of a State often encompassing several towns or perhaps a city, not all States have them & their application varies greatly.

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      I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
    3. Re:The county would never have noticed by maggard · · Score: 2
      Objects in space don't contend with an atmosphere. For ones under a 50m diameter this is a crucial difference, for ones over 100m not so important. For more details see this posting.

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      I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
    4. Re:The county would never have noticed by maggard · · Score: 2
      B'cause they not propelled (or are you of the "Greys" school of thought?)

      Objects generally enter the atmosphere at 10-30Kps if they're asteroidial in origin, 40-70Kps if cometary. If they're big enough aerodynamic effects are negligable - that's a couple hundred meters in diameter & would have disasterous effect upon impact.

      However for objects below 50 meters the atmosphere is all crucial - they'll often get so chewed up that nothing makes it down coherent (depends on trajectory, composition and how it comes apart.)

      As this object was only a few meters in size initially it's unlikely (though not impossible) that anything recognizable made it to the surface. Certianly it was well within the size limit at which it would have been slowed to it's terminal velocity.

      Once folks get away from this idea that we're talking about giant objects slamming into the surface at impossible speeds it all becomes much more realistic. Meteors are bright, they're definitely very impressive coming down, but all of that energy is from the object slowing & ablating.

      In this case one could simulate the impact by dropping a frozen cannonball or dense rock from a 30 story or so height, possibly just tossing some gravel or ball bearings, most likely dust. Not exactly gonna cause disaster in the county huh?

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      I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
    5. Re:The county would never have noticed by p3d0 · · Score: 2
      No take a look at the speed - I don't actually know what the terminal velocity of of rock is but I'm guessing 150-300 MPH.
      Why would you think that a meteor would be limited by terminal velocity?
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      Patrick Doyle
      I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
    6. Re:The county would never have noticed by matman · · Score: 2

      Terminal velocity is not an instant thing... it takes time to reach terminal velocity. Objects in space travel at huge speeds... many many thousands of km/hour. The object would not have decelerated to terminal velocity before it hit the ground. If you look at the damage that screws cause when they collide with spacecraft in space, you'll see why a small meteorite could cause HUGE damage.

  2. Re:Unsurprising... by maggard · · Score: 2

    Starts out car sized at the top of the atmosphere, ends up baseball-sized or smaller at the bottom if anything at all makes it to the surface (depends on trajectory, composition, and how the thing ablates.)

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    I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
  3. Re:Oddly enough... by sharkey · · Score: 2

    Apparently, he had a sign that said, "Ten dollars to see it, twenty dollars to watch me jack off."

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    "Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
  4. Did you read the story? by RebornData · · Score: 2

    Quote:

    "If this was a rocky asteroid, then it probably measured between 1 and 2 meters across and weighed 30 or so metric tons."

    That sounds at least "car sized" by any definition I can think of.

    If a car-sized meteor*ite* landed, it would definitely been bigger news...

  5. Re:Unsurprising... by miahrogers · · Score: 2

    They said it was car-sized, never said it weight as much as a car.

  6. Re:This is irrational fear #1 by cr0sh · · Score: 2

    I don't know about a penny, but I have seen what happens when a bolt fall off the top of an oil derrick and hits someone's helmet:

    Think 2 inch deep impact mark.

    Fortunately, the helmet was steel, and the person I knew who had this happen to him (I was a kid at the time) didn't get killed...

    Worldcom - Generation Duh!

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    Reason is the Path to God - Anon
  7. Indulge both your fears! by dmaxwell · · Score: 2

    How about a Ningi dropped on the planet from space?

    "Money
    Monetary units - none.

    In fact there are three freely convertible currencies in the Galaxy, but none of them count. The Altairian Dollar has recently collapsed, the Flanian Pobble bead is only exchangeable for other Flanian Pobble Beads, and the Triganic Pu has its own very special problems. Its exchange rate of eight Ningis to one Pu is simple enough, but since a Ningi is a rubber coin six thousand eight hundred miles along each side, no one has ever collected enough to own one Pu. Ningis are not negotiable currency, because the Galactibanks refuse to deal in fiddling small change. From this basic premise it is very simple to prove that the Galactibanks are also the product of a deranged imagination."

    Just think of the havoc THAT hyperaccelerated piece of small change would cause.

  8. oh, THOSE kind of aliens! by SirSlud · · Score: 2

    >was very small, disintegrated before impact, and anything that might have reached the ground intact would have been cold to the touch

    so what they're saying is that the UFO was small, capable of disintegration at very high speeds (obviously a sign of an advanced life form), and cold, eh? They were probably just searching for some nice hot cambells chick noodle soup ...

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    "Old man yells at systemd"
  9. In other news... by szcx · · Score: 2

    A Smallville couple, Mr. and Mrs. Kent, were arrested today on child kidnapping charges. The couple alleges they "found" the child in a corn field near their farm. Mr. Kent is undergoing tests at the Smallville Psychiatric Hospital while the authorities attempt to locate the childs parents.

  10. Eyewitness Report by carlhirsch · · Score: 2

    Unnamed witnesses spoke of seeing author Stephen King dressed as a hayseed and approaching the object one it landed.

    Witnesses heard Mr. King exclaim "Meteor shit!" at which point he smabled back to his shotgun shack muttering abuot "washing it off."

    Mr. King was later unable to be found for comment. However, his shack did appear to be very well-stocked with houseplants and lush flora.

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    . We've got computers, we're tapping phone lines, you know that ain't allowed - Talking Heads, "Life During Wartime"
  11. Oddly enough... by daeley · · Score: 4

    According to the report, Mark Wahlberg emerged from the 'object.'

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    I watched C-beams glitter in the dark near the Tannhauser gate.
  12. Too bad it wasn't just a bit bigger... by starseeker · · Score: 2

    Of course you don't want anyone hurt or any serious damage done, but these things are great for science. They contain a lot of information about the early solar system that got chewed up on Earth a long time ago. Life on Mars nonwithstanding there are a lot of worthwhile questions which can be answered by meteors, such as what conditions were like when the planets were forming. (That's also one of the things moon rocks are good for...)

    Plus, on a social note, now we don't get another round of asteroid movies. So much for seeing Jim Carrey climbing around on a metor and screaming as he gets stuck and rides it into Cleveland...

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    "I object to doing things that computers can do." -- Olin Shivers, lispers.org
  13. Re:I hope this scares my Grandma by beable · · Score: 2
    I heard them say that scientists were speculating that something called a bolus, I think, fell from space, broke up, and burned as it fell towards Earth. I almost choked at the stupidity of it. We just call those things in space meteors, and if they hit the planet surface they are meteorites.
    Actually, according to the story, scientists call that sort of phenomenon a "bolide":
    the terms fireball and bolide are often confused -- even by professional astronomers. A fireball is a meteor at least as bright as the planet Venus (visual magnitude -3 or -4). A bolide is a fireball that explodes, often with sound effects.
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  14. Did anybody listen to the mp3? by SCHecklerX · · Score: 2

    Do I detect a lisp?

  15. Over the top? by geekplus · · Score: 3
    Then perhaps you'd care to explain the 8" diameter, heat-cauterized, crater in my chest?

    No, the answer is not Cowboy Neal!

  16. Unsurprising... by nanojath · · Score: 5
    This is unsurprising, since a car-sized metor would have basically blown up a good size chunk of whatever county it landed in, not just scorched a cornfield.

    Actually, for that matter if you read the original story it was saying baseball sized or thereabouts. If anything was the size of a car, maybe the fireball was, but that says next to nothing about the size of the actual meteor.

    Believe me, when a car-sized meteor hits a populated area you won't need to go to Slashdot to hear the story.

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    It Is the Nature of Information to Transgress Artificial Boundaries

  17. This is irrational fear #1 by MulluskO · · Score: 2

    If a penny dropped from a very tall building is capable of killing someone, I worry about thousands of peices of rocks falling from the sky. I'm not comfortable thinking about the possiblility that my life could be suddenly and unexpectedly ended by an event so stupid. It's better to stay inside and post on Slashdot.

    My #2 irrational fear?
    Getting hit with a super-accelerated penny.

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    Too busy staying alive... ~ R.A.
  18. Re:well, by MulluskO · · Score: 2

    If they were car-sized in the U.S. they would be Europe-sized.

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    Too busy staying alive... ~ R.A.
  19. If it were that large at impact, yes... by CoachS · · Score: 2
    ...but according to NASA while it might have been a couple of meters across, and 30 metric tons, when it entered the atmosphere, it certainly was nowhere near that when it impacted the group -- if it even did.

    Preliminary reports from the cornfield seem to indicate little or no evidence of an actual impact; which would seem to indicate that whatever it was burned up before it reached the ground (as they usually do).

    -Coach-

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    Perhaps the world's greatest tragedy is that ignorance is not impotence.
  20. well, by cosmo7 · · Score: 4

    if they had fallen in Europe they'd be car-sized.

  21. I told you I told you!! by pj7 · · Score: 2

    Space has a terrible secret!
    But did any of you listen? Now please, go stand by the stairs, the space robots are coming to protect us.