Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 16/09/2006 20:40:58
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Dearest Space People,
Why is it that for the most part, meteors blow up just before reaching ground level ?...or did I hear that wrong ?...it's just that I sure I have heard accounts that ' the meteor exploded before impact '....why is that ?
Thanks
Men are the same as women, just inside out !
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Does it have something to do with temperature changes and air pressure differences!
Karen
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It is not that meteors blow up 'just before' impact; it is rather that as the meteor enters the earths atmosphere, it get very hot (due air friction at hypersonic velocities), and unless the meteor is very large, its fate is much like that of the Columbia space shuttle when it entered the atmosphere with a hole in its skin - it gets very hot, until it either just evaporates or explodes (or maybe both).
George
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Hmmmm well temperature maybe then! You mean friction between the meteor and the air or atmosphere?
Karen
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Not sure what you mean by 'air' or 'atmosphere'? Is not the Earth's atmosphere composed of air?
George
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No the main atmosphere of the earth is liquid Hydrogen dioxide, the amount of Nitrogen, Oxygen, etc is trivial in comparison.
syhprum
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quote:
Originally posted by syhprum
No the main atmosphere of the earth is liquid Hydrogen dioxide, the amount of Nitrogen, Oxygen, etc is trivial in comparison.
syhprum
Do you really mean hydrogen dioxide, or are you talking about dihydrogen oxide?
George
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quote:
Originally posted by syhprum
No the main atmosphere of the earth is liquid Hydrogen dioxide, the amount of Nitrogen, Oxygen, etc is trivial in comparison.
You are not saying it seriously, is it?
Composition of
dry atmosphere, by volume ppmv: parts per million by volume
Gas Volume
Nitrogen (N2) 780,840 ppmv (78.084%)
Oxygen (O2) 209,460 ppmv (20.946%)
Argon (Ar) 9,340 ppmv (0.9340%)
Carbon dioxide (CO2) 381 ppmv
Neon (Ne) 18.18 ppmv
Helium (He) 5.24 ppmv
Methane (CH4) 1.745 ppmv
Krypton (Kr) 1.14 ppmv
Hydrogen (H2) 0.55 ppmv
Not included in above dry atmosphere:
Water vapor (H2O) typically 1% to 4%(highly variable)
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quote:
Originally posted by another_someone
Not sure what you mean by 'air' or 'atmosphere'? Is not the Earth's atmosphere composed of air?
George
Yes friend it is![;)] I do not know however, all of the other components as science is not my best subject but enlighten me plese! whoops I see someone has Thank you all! My wording is very poor appologies. I have had 8 hours of last 3 days or is this 4, i don't know...sorry![:D]
Karen
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Of course I meant dihydrogen oxide, the mass of this exceeds by a factor of at least 1500 that of other atmospheric components and once the sun warms up and it is no longer liquified it will form the main component of the atmosphere
syhprum
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Meteors do not always blow up. Sometimes they hit and form craters. A meteor coming in very fast, like 1/3 light speed hit Russia around 1900-10. The atmosphere beneath it could not move out of the way and at extremely high pressures it exploded like an atomic bomb. The gas was fissile. The meteor was destroyed. The forest was shattered and flattened except directly beneath, where the trees remained standing. Like the Budhist temple in one of the WW2 Japanese cities, directly beneath the bomb.
It matters about the relationship of the fissile material in relation to the earth and sun and probably the neutron refraction or reflection as it may be. So that could have been a fairly big carbonaceous or iron meteor.
Titanscape
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Sorry shat's rubbish Titanscape the 1910 russian meteor was a good example of the exploding type of meteor it comes in at a normal meteoric speed high tens of miles per second and nothing like light velocity and has nothing to do with nuclear fission
Some meteors are very solid like rocks or chunks of metal and will stand a lot of heat and stress but others are a bit like a mobile beach with lots of little bits loosely bound together by weak self gravity and a bit of ice. When one of these comes into the atmosphere particularly if it comes in at a lowish angle. It starts to break up and fragments in stages into millions of tiny particles each of which burns up in the lower atmosphere as a brilliant fireball brighter than venus If you get a few million venuses glowing at the same time its brighter than the sun and can be about as bright as a nuclear air blast that can burn a forest . This also creates a violent shock wave that can knock down trees. The whole thing burns up in a second or two and there is little or no solid evidence other than the heat and shockwave effects.
Learn, create, test and tell
evolution rules in all things
God says so!
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I agree I am at a loss to see how any body could be accelerated to 100,000 Km/s except maybe by a black hole and I am sure we would have noticed it if there was one nearby.
syhprum
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Seagulls explode before they hit the ground if you throw Alka Seltzer tablets to them [:D]
Brand new forum at
http://beaverland.forumup.us
More than just science
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Does it have something to do with temperature changes and air pressure differences!
Karen
-
It is not that meteors blow up 'just before' impact; it is rather that as the meteor enters the earths atmosphere, it get very hot (due air friction at hypersonic velocities), and unless the meteor is very large, its fate is much like that of the Columbia space shuttle when it entered the atmosphere with a hole in its skin - it gets very hot, until it either just evaporates or explodes (or maybe both).
George
-
Hmmmm well temperature maybe then! You mean friction between the meteor and the air or atmosphere?
Karen
-
Not sure what you mean by 'air' or 'atmosphere'? Is not the Earth's atmosphere composed of air?
George
-
No the main atmosphere of the earth is liquid Hydrogen dioxide, the amount of Nitrogen, Oxygen, etc is trivial in comparison.
syhprum
-
quote:
Originally posted by syhprum
No the main atmosphere of the earth is liquid Hydrogen dioxide, the amount of Nitrogen, Oxygen, etc is trivial in comparison.
syhprum
Do you really mean hydrogen dioxide, or are you talking about dihydrogen oxide?
George
-
quote:
Originally posted by syhprum
No the main atmosphere of the earth is liquid Hydrogen dioxide, the amount of Nitrogen, Oxygen, etc is trivial in comparison.
You are not saying it seriously, is it?
Composition of
dry atmosphere, by volume ppmv: parts per million by volume
Gas Volume
Nitrogen (N2) 780,840 ppmv (78.084%)
Oxygen (O2) 209,460 ppmv (20.946%)
Argon (Ar) 9,340 ppmv (0.9340%)
Carbon dioxide (CO2) 381 ppmv
Neon (Ne) 18.18 ppmv
Helium (He) 5.24 ppmv
Methane (CH4) 1.745 ppmv
Krypton (Kr) 1.14 ppmv
Hydrogen (H2) 0.55 ppmv
Not included in above dry atmosphere:
Water vapor (H2O) typically 1% to 4%(highly variable)
-
quote:
Originally posted by another_someone
Not sure what you mean by 'air' or 'atmosphere'? Is not the Earth's atmosphere composed of air?
George
Yes friend it is![;)] I do not know however, all of the other components as science is not my best subject but enlighten me plese! whoops I see someone has Thank you all! My wording is very poor appologies. I have had 8 hours of last 3 days or is this 4, i don't know...sorry![:D]
Karen
-
Of course I meant dihydrogen oxide, the mass of this exceeds by a factor of at least 1500 that of other atmospheric components and once the sun warms up and it is no longer liquified it will form the main component of the atmosphere
syhprum
-
Meteors do not always blow up. Sometimes they hit and form craters. A meteor coming in very fast, like 1/3 light speed hit Russia around 1900-10. The atmosphere beneath it could not move out of the way and at extremely high pressures it exploded like an atomic bomb. The gas was fissile. The meteor was destroyed. The forest was shattered and flattened except directly beneath, where the trees remained standing. Like the Budhist temple in one of the WW2 Japanese cities, directly beneath the bomb.
It matters about the relationship of the fissile material in relation to the earth and sun and probably the neutron refraction or reflection as it may be. So that could have been a fairly big carbonaceous or iron meteor.
Titanscape
-
Sorry shat's rubbish Titanscape the 1910 russian meteor was a good example of the exploding type of meteor it comes in at a normal meteoric speed high tens of miles per second and nothing like light velocity and has nothing to do with nuclear fission
Some meteors are very solid like rocks or chunks of metal and will stand a lot of heat and stress but others are a bit like a mobile beach with lots of little bits loosely bound together by weak self gravity and a bit of ice. When one of these comes into the atmosphere particularly if it comes in at a lowish angle. It starts to break up and fragments in stages into millions of tiny particles each of which burns up in the lower atmosphere as a brilliant fireball brighter than venus If you get a few million venuses glowing at the same time its brighter than the sun and can be about as bright as a nuclear air blast that can burn a forest . This also creates a violent shock wave that can knock down trees. The whole thing burns up in a second or two and there is little or no solid evidence other than the heat and shockwave effects.
Learn, create, test and tell
evolution rules in all things
God says so!
-
I agree I am at a loss to see how any body could be accelerated to 100,000 Km/s except maybe by a black hole and I am sure we would have noticed it if there was one nearby.
syhprum
-
Seagulls explode before they hit the ground if you throw Alka Seltzer tablets to them [:D]
Brand new forum at
http://beaverland.forumup.us
More than just science
-
Are you sure it wasn't like 1/3000 or 1/30,000 of the speed of light? [;)]
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Exactly. I read typical meteor's speed is around 10 - 70 Km/second.
About Tunguska forest event(1908) someone said it could have been a little comet exploding not far from the ground.
http://en.wikipedia.org/wiki/Tunguska_event
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Are you sure it wasn't like 1/3000 or 1/30,000 of the speed of light? [;)]
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Exactly. I read typical meteor's speed is around 10 - 70 Km/second.
About Tunguska forest event(1908) someone said it could have been a little comet exploding not far from the ground.
http://en.wikipedia.org/wiki/Tunguska_event