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I was told that more meteorites fall onto the southern hemisphere than the northern. Is this true - and if so: what is the reason? Thanks for replies - Klaus http://www.oz-greetings.com.au Nature Wilderness Geology
blacklight wrote: > I was told that more meteorites fall onto the southern hemisphere than > the northern.
That would make no sense that one hemisphere would be sought out by meteors. Because Australia has a lot of light sedimentary rock and Antarctica is white, it is probably easier to FIND meteorites in the southern hemisphere.
On Nov 6, 6:22 pm, Sam Wormley <sworml...@mchsi.com> wrote:
> blacklight wrote: > > I was told that more meteorites fall onto the southern hemisphere than > > the northern. > That would make no sense that one hemisphere would be sought out by > meteors. Because Australia has a lot of light sedimentary rock and > Antarctica is white, it is probably easier to FIND meteorites in the > southern hemisphere.
On the other hand, a higher proportion of meteorites that fall in the southern hemisphere... end up on the bottom of the ocean.
The word “Muslim” means one who submits to the will of God, regardless of their race, nationality or ethnic background. Becoming a Muslim is a simple and easy process that requires no pre-requisites. One may convert alone in privacy, or he/she may do so in the presence of others. If anyone has a real desire to be a Muslim and has full conviction and strong belief that Islam is the true religion of God, then, all one needs to do is pronounce the “Shahada”, the testimony of faith, without further delay. The “Shahada” is the first and most important of the five pillars of Islam. With the pronunciation of this testimony, or “Shahada”, with sincere belief and conviction, one enters the fold of Islam. Upon entering the fold of Islam purely for the Pleasure of God, all of one’s previous sins are forgiven, and one starts a new life of piety and righteousness. The Prophet said to a person who had placed the condition upon the Prophet in accepting Islam that God would forgive his sins: “Do you not know that accepting Islam destroys all sins which come before it?” (Saheeh Muslim) When one accepts Islam, they in essence repent from the ways and beliefs of their previous life. One need not to be overburdened by sins committed before their acceptance. The person’s record is clean, and it is as if he was just born from his mother’s womb. One should try as much as possible to keep his records clean and strive to do as many good deeds as possible. The Holy Quran and Hadeeth (prophetic sayings) both stress the importance of following Islam. God states: “…The only religion in the sight of God is Islam…” (Quran 3:19) In another verse of the Holy Quran, God states: “If anyone desires a religion other than Islam, never will it be accepted of him; and in the Hereafter, he will be in the ranks of those who have lost (their selves in the Hellfire).” (Quran 3:85) In another saying, Muhammad, the Prophet of God, said: “Whoever testifies that there in none worthy of being worshipped but God, Who has no partner, and that Muhammad is His slave and Prophet, and that Jesus is the Slave of God, His Prophet, and His word[1] which He bestowed in Mary and a spirit created from Him; and that Paradise (Heaven) is true, and that the Hellfire is true, God will eventually admit him into Paradise, according to his deeds.” (Saheeh Al-Bukhari) The Prophet of God, may God praise him, also reported: “Indeed God has forbidden to reside eternally in Hell the person who says: “I testify that none has the right to worship except Allah (God),’ seeking thereby the Face of God.” (Saheeh Al-Bukhari) The Declaration of the Testimony (Shahada) To convert to Islam and become a Muslim a person needs to pronounce the below testimony with conviction and understanding its meaning: I testify “La ilah illa Allah, Muhammad rasoolu Allah.” The translation of which is: “I testify that there is no true god (deity) but God (Allah), and that Muhammad is a Messenger (Prophet) of God.” To hear it click here or click on “Live Help” above for assistance by chat. When someone pronounces the testimony with conviction, then he/she have become a Muslim. It can be done alone, but it is much better to be done with an adviser through the “Live Help” at top, so he may help you in pronouncing it right. The first part of the testimony consists of the most important truth that God revealed to mankind: that there is nothing divine or worthy of being worshipped except for Almighty God. God states in the Holy Quran: “We did not send the Messenger before you without revealing to him: ‘none has the right to be worshipped except I, therefore worship Me.’” (Quran 21:25) This conveys that all forms of worship, whether it be praying, fasting, invoking, seeking refuge in, and offering an animal as sacrifice, must be directed to God and to God alone. Directing any form of worship to other than God (whether it be an angel, a messenger, Jesus, Muhammad, a saint, an idol, the sun, the moon, a tree) is seen as a contradiction to the fundamental message of Islam, and it is an unforgivable sin unless it is repented from before one dies. All forms of worship must be directed to God only. Worship means the performance of deeds and sayings that please God, things which He commanded or encouraged to be performed, either by direct textual proof or by analogy. Thus, worship is not restricted to the implementation of the five pillars of Islam, but also includes every aspect of life. Providing food for one’s family, and saying something pleasant to cheer a person up are also considered acts of worship, if such is done with the intention of pleasing God. This means that, to be accepted, all acts of worship must be carried out sincerely for the Sake of God alone. The second part of the testimony means that Prophet Muhammad is the servant and chosen messenger of God. This implies that one obeys and follows the commands of the Prophet. One must believe in what he has said, practice his teachings and avoid what he has forbidden. One must therefore worship God only according to his teaching alone, for all the teachings of the Prophet were in fact revelations and inspirations conveyed to him by God. One must try to mold their lives and character and emulate the Prophet, as he was a living example for humans to follow. God says: “And indeed you are upon a high standard of moral character.” (Quran 68:4) God also said: “And in deed you have a good and upright example in the Messenger of God, for those who hope in the meeting of God and the Hereafter, and mentions God much.” (Quran 33:21) He was sent in order to practically implement the Quran, in his saying, deeds, legislation as well as all other facets of life. Aisha, the wife of the Prophet, when asked about the character of the Prophet, replied: “His character was that of the Quran.” (As-Suyooti) To truly adhere to the second part of the Shahada is to follow his example in all walks of life. God says: “Say (O Muhammad to mankind): ‘If you (really) love God, then follow me.’” (Quran 3:31) It also means that Muhammad is the Final Prophet and Messenger of God, and that no (true) Prophet can come after him. “Muhammad is not the father of any man among you but he is the Messenger of God and the last (end) of the Prophets and God is Ever All-Aware of everything.” (Quran 33:40) All who claim to be prophets or receive revelation after Muhammad are imposters, and to acknowledge them would be tantamount to disbelief. We welcome you to Islam, congratulate you for your decision, and will try to help you in any way we can.
The word “Muslim” means one who submits to the will of God, regardless of their race, nationality or ethnic background. Becoming a Muslim is a simple and easy process that requires no pre-requisites. One may convert alone in privacy, or he/she may do so in the presence of others. If anyone has a real desire to be a Muslim and has full conviction and strong belief that Islam is the true religion of God, then, all one needs to do is pronounce the “Shahada”, the testimony of faith, without further delay. The “Shahada” is the first and most important of the five pillars of Islam. With the pronunciation of this testimony, or “Shahada”, with sincere belief and conviction, one enters the fold of Islam. Upon entering the fold of Islam purely for the Pleasure of God, all of one’s previous sins are forgiven, and one starts a new life of piety and righteousness. The Prophet said to a person who had placed the condition upon the Prophet in accepting Islam that God would forgive his sins: “Do you not know that accepting Islam destroys all sins which come before it?” (Saheeh Muslim) When one accepts Islam, they in essence repent from the ways and beliefs of their previous life. One need not to be overburdened by sins committed before their acceptance. The person’s record is clean, and it is as if he was just born from his mother’s womb. One should try as much as possible to keep his records clean and strive to do as many good deeds as possible. The Holy Quran and Hadeeth (prophetic sayings) both stress the importance of following Islam. God states: “…The only religion in the sight of God is Islam…” (Quran 3:19) In another verse of the Holy Quran, God states: “If anyone desires a religion other than Islam, never will it be accepted of him; and in the Hereafter, he will be in the ranks of those who have lost (their selves in the Hellfire).” (Quran 3:85) In another saying, Muhammad, the Prophet of God, said: “Whoever testifies that there in none worthy of being worshipped but God, Who has no partner, and that Muhammad is His slave and Prophet, and that Jesus is the Slave of God, His Prophet, and His word[1] which He bestowed in Mary and a spirit created from Him; and that Paradise (Heaven) is true, and that the Hellfire is true, God will eventually admit him into Paradise, according to his deeds.” (Saheeh Al-Bukhari) The Prophet of God, may God praise him, also reported: “Indeed God has forbidden to reside eternally in Hell the person who says: “I testify that none has the right to worship except Allah (God),’ seeking thereby the Face of God.” (Saheeh Al-Bukhari) The Declaration of the Testimony (Shahada) To convert to Islam and become a Muslim a person needs to pronounce the below testimony with conviction and understanding its meaning: I testify “La ilah illa Allah, Muhammad rasoolu Allah.” The translation of which is: “I testify that there is no true god (deity) but God (Allah), and that Muhammad is a Messenger (Prophet) of God.” To hear it click here or click on “Live Help” above for assistance by chat. When someone pronounces the testimony with conviction, then he/she have become a Muslim. It can be done alone, but it is much better to be done with an adviser through the “Live Help” at top, so he may help you in pronouncing it right. The first part of the testimony consists of the most important truth that God revealed to mankind: that there is nothing divine or worthy of being worshipped except for Almighty God. God states in the Holy Quran: “We did not send the Messenger before you without revealing to him: ‘none has the right to be worshipped except I, therefore worship Me.’” (Quran 21:25) This conveys that all forms of worship, whether it be praying, fasting, invoking, seeking refuge in, and offering an animal as sacrifice, must be directed to God and to God alone. Directing any form of worship to other than God (whether it be an angel, a messenger, Jesus, Muhammad, a saint, an idol, the sun, the moon, a tree) is seen as a contradiction to the fundamental message of Islam, and it is an unforgivable sin unless it is repented from before one dies. All forms of worship must be directed to God only. Worship means the performance of deeds and sayings that please God, things which He commanded or encouraged to be performed, either by direct textual proof or by analogy. Thus, worship is not restricted to the implementation of the five pillars of Islam, but also includes every aspect of life. Providing food for one’s family, and saying something pleasant to cheer a person up are also considered acts of worship, if such is done with the intention of pleasing God. This means that, to be accepted, all acts of worship must be carried out sincerely for the Sake of God alone. The second part of the testimony means that Prophet Muhammad is the servant and chosen messenger of God. This implies that one obeys and follows the commands of the Prophet. One must believe in what he has said, practice his teachings and avoid what he has forbidden. One must therefore worship God only according to his teaching alone, for all the teachings of the Prophet were in fact revelations and inspirations conveyed to him by God. One must try to mold their lives and character and emulate the Prophet, as he was a living example for humans to follow. God says: “And indeed you are upon a high standard of moral character.” (Quran 68:4) God also said: “And in deed you have a good and upright example in the Messenger of God, for those who hope in the meeting of God and the Hereafter, and mentions God much.” (Quran 33:21) He was sent in order to practically implement the Quran, in his saying, deeds, legislation as well as all other facets of life. Aisha, the wife of the Prophet, when asked about the character of the Prophet, replied: “His character was that of the Quran.” (As-Suyooti) To truly adhere to the second part of the Shahada is to follow his example in all walks of life. God says: “Say (O Muhammad to mankind): ‘If you (really) love God, then follow me.’” (Quran 3:31) It also means that Muhammad is the Final Prophet and Messenger of God, and that no (true) Prophet can come after him. “Muhammad is not the father of any man among you but he is the Messenger of God and the last (end) of the Prophets and God is Ever All-Aware of everything.” (Quran 33:40) All who claim to be prophets or receive revelation after Muhammad are imposters, and to acknowledge them would be tantamount to disbelief. We welcome you to Islam, congratulate you for your decision, and will try to help you in any way we can.
On Nov 6, 4:49 pm, blacklight <i...@oz-greetings.com.au> wrote:
> I was told that more meteorites fall onto the southern hemisphere than > the northern. Is this true - and if so: what is the reason? > Thanks for replies - Klaushttp://www.oz-greetings.com.au > Nature Wilderness Geology
It might be that, over geological time spans, that there isn't any difference.
Perhaps also that in our rerorded history there might be more, right now anyway, becasue some source of 'flying space rock' to coin a term is coming at the Solar System from the 'Southernly Direction'.
On Nov 7, 7:14 pm, TBerk <bayareab...@yahoo.com> wrote:
> Perhaps also that in our rerorded history there might be more, right > now anyway, becasue some source of 'flying space rock' to coin a term > is coming at the Solar System from the 'Southernly Direction'.
Generally speaking, though, it is believed that the meteorites that reach Earth are material that was originally in orbit in our Solar System, not Galactic debris. So I don't think that's a possibility.
Nearly all meteorites belong to one of the groups of asteroidal material types - a few are rocks knocked into space from the Moon or even Mars by larger impacts on those bodies.
On Nov 6, 10:08 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
> On Nov 6, 6:22 pm, Sam Wormley <sworml...@mchsi.com> wrote:
> > blacklight wrote: > > > I was told that more meteorites fall onto the southern hemisphere than > > > the northern. > > That would make no sense that one hemisphere would be sought out by > > meteors. Because Australia has a lot of light sedimentary rock and > > Antarctica is white, it is probably easier to FIND meteorites in the > > southern hemisphere.
> On the other hand, a higher proportion of meteorites that fall in the > southern hemisphere... end up on the bottom of the ocean.
Meteorites do not fall, unless someone picks them up and drops them. They rest on the Earth's surface (or on layers of ice, or on someone's dining room floor, etc.)
On Sun, 8 Nov 2009 07:17:38 -0800 (PST), wsnel...@hotmail.com wrote: >Meteorites do not fall, unless someone picks them up and drops them. >They rest on the Earth's surface (or on layers of ice, or on someone's >dining room floor, etc.)
An object that survives ablation in the atmosphere is correctly called a meteorite while it is falling. So we talk about the dark flight of the meteorite, or the aerodynamics of the meteorite as it falls. _________________________________________________
> Meteorites do not fall, unless someone picks them up and drops them. > They rest on the Earth's surface (or on layers of ice, or on someone's > dining room floor, etc.)
A meteorite is something that fell back when it was a meteor, so, yes, it would perhaps have been more precise of me to say that "a higher proportion of meteorites that _have fallen_ in the southern hemisphere".
Of course I could have said "meteor" instead of "meteorites", but then I'd be talking about something else, because most meteors burn up before they reach the ground.
"a higher proportion of those meteors that fall in the southern hemisphere, if they survive to become meteorites... end up at the bottom of the ocean" - ah, yes, it _is_ possible to construct a correct and coherent sentence in this regard.
On Nov 8, 10:57 am, Chris L Peterson <c...@alumni.caltech.edu> wrote:
> On Sun, 8 Nov 2009 07:17:38 -0800 (PST), wsnel...@hotmail.com wrote: > >Meteorites do not fall, unless someone picks them up and drops them. > >They rest on the Earth's surface (or on layers of ice, or on someone's > >dining room floor, etc.)
> An object that survives ablation in the atmosphere is correctly called a > meteorite while it is falling. So we talk about the dark flight of the > meteorite, or the aerodynamics of the meteorite as it falls.
It must not only survive ablation, it must survive the impact. And once it does that it is no longer falling.
On Fri, 6 Nov 2009 16:49:33 -0800 (PST), blacklight
<i...@oz-greetings.com.au> wrote: >I was told that more meteorites fall onto the southern hemisphere than >the northern. Is this true - and if so: what is the reason?
Meteor streams are not uniformly distributed. It is well known that there is a northern hemisphere bias for meteor showers, for example. These are largely of cometary origin, and don't produce meteorites, but similar asymmetries are noted for other meteor origins, including sporadic meteors that can produce meteorites. So a slight bias is possible, but it would change with time- probably over a few thousand years.
Meteorites are divided into two categories, "finds" which are any recovery, and "falls", which are finds associated with observed meteors or actually witnessing the meteorite hitting the ground. Falls are rare, accounting for only a few percent at most of meteorites. There are not enough to make any statistically valid assessment of whether falls are more common in the northern or southern hemisphere. It is also difficult to make any reasonable assessment in terms of total meteorite count between the north and south, given the many factors that influence finds: population, land area, type of land. _________________________________________________
On Sun, 8 Nov 2009 08:58:12 -0800 (PST), wsnel...@hotmail.com wrote: >It must not only survive ablation, it must survive the impact. And >once it does that it is no longer falling.
That is not the usual usage. The reason we consider them meteorites while still in the air after ablation is simple: if they survive ablation, they will survive impact. Always. _________________________________________________
> > Meteorites do not fall, unless someone picks them up and drops them. > > They rest on the Earth's surface (or on layers of ice, or on someone's > > dining room floor, etc.)
> A meteorite is something that fell back when it was a meteor, so, yes, > it would perhaps have been more precise of me to say that "a higher > proportion of meteorites that _have fallen_ in the southern > hemisphere".
> Of course I could have said "meteor" instead of "meteorites", but then > I'd be talking about something else, because most meteors burn up > before they reach the ground.
> "a higher proportion of those meteors that fall in the southern > hemisphere, if they survive to become meteorites... end up at the > bottom of the ocean" - ah, yes, it _is_ possible to construct a > correct and coherent sentence in this regard.
> John Savard
Definitions can get fuzzy. A meteoroid that enters a planet's atmosphere on a grazing trajectory, survives ablation and then heads back out into space without reaching the planet's surface must still be a meteoroid, not a meteorite. If it followed the same sort of trajectory near the Moon, it would obviously not be called a meteorite.
Meteors don't burn up in the atmosphere, they are the visual phenomena seen as the actual object passes through the atmosphere.
> >Meteorites do not fall, unless someone picks them up and drops them. > >They rest on the Earth's surface (or on layers of ice, or on someone's > >dining room floor, etc.)
Chris L Peterson:
> An object that survives ablation in the atmosphere is correctly called a > meteorite while it is falling. So we talk about the dark flight of the > meteorite, or the aerodynamics of the meteorite as it falls.
But only by changing its name _after_ it strikes the Earth. I think the issue is a bit tricky. On the one hand, one might analyze a meteorite and pronounce that "this meteorite" came from Mars and "this meteorite" traveled for n million years before striking the Earth, etc, etc. One would be (correctly) describing an object that had been flying through space as a meteorite.
OTOH, if you're at a public event and a meteor streaks through the sky and Mary Q. says "Wow, did you see that meteorite," and if it's an educational event, you will tell Mary that it's called a meteor and it won't be called a meteorite until and unless it strikes the Earth. When it conveniently falls at (not on) your feet* so that you can pick it up, it is unarguably a meteorite.
But it seems to me that, since you would not call it a meteorite while it was only a bright streak in the sky, when you begin to talk about the meteorite's dark flight or about having seen it streaking toward you, you are revising its entire history of n billion years -- "this meteorite probably originated..." Now it was a meteorite from the moment of its origin. It's Schrödinger's meteor/meteorite.
In short, I think you are quite correct and quite mistaken.
Davoud
*Better it should hit my representative, who last night voted for his job security in a congressional district that tends toward social regressiveness, and against the safety and security of the American people. If it happened to a common person her "health insurance" company, if she had one, would likely declare that being hit by a meteor(ite) is a pre-existing condition.
On Nov 8, 12:34 pm, Chris L Peterson <c...@alumni.caltech.edu> wrote:
> On Sun, 8 Nov 2009 08:58:12 -0800 (PST), wsnel...@hotmail.com wrote: > >It must not only survive ablation, it must survive the impact. And > >once it does that it is no longer falling.
> That is not the usual usage. The reason we consider them meteorites > while still in the air after ablation is simple: if they survive > ablation, they will survive impact. Always.
> > >Meteorites do not fall, unless someone picks them up and drops them. > > >They rest on the Earth's surface (or on layers of ice, or on someone's > > >dining room floor, etc.)
> Chris L Peterson:
> > An object that survives ablation in the atmosphere is correctly called a > > meteorite while it is falling. So we talk about the dark flight of the > > meteorite, or the aerodynamics of the meteorite as it falls.
> But only by changing its name _after_ it strikes the Earth. I think the > issue is a bit tricky. On the one hand, one might analyze a meteorite > and pronounce that "this meteorite" came from Mars and "this meteorite" > traveled for n million years before striking the Earth, etc, etc. One > would be (correctly) describing an object that had been flying through > space as a meteorite.
It is a bit difficult to think of the object that caused the famous August, '72 fireball as a meteorite. It is also difficult to think of a meteoroid that survives the ablation only to fracture into pieces on impact as having survived the impact. The pieces that are found are called meteorites, but not the body that is still falling. That is a meteoroid.
> OTOH, if you're at a public event and a meteor streaks through the sky > and Mary Q. says "Wow, did you see that meteorite," and if it's an > educational event, you will tell Mary that it's called a meteor and it > won't be called a meteorite until and unless it strikes the Earth. When > it conveniently falls at (not on) your feet* so that you can pick it > up, it is unarguably a meteorite.
> But it seems to me that, since you would not call it a meteorite while > it was only a bright streak in the sky, when you begin to talk about > the meteorite's dark flight or about having seen it streaking toward > you, you are revising its entire history of n billion years -- "this > meteorite probably originated..." Now it was a meteorite from the > moment of its origin. It's Schrödinger's meteor/meteorite.
> In short, I think you are quite correct and quite mistaken.
> Davoud
> *Better it should hit my representative, who last night voted for his > job security in a congressional district that tends toward social > regressiveness, and against the safety and security of the American > people. If it happened to a common person her "health insurance" > company, if she had one, would likely declare that being hit by a > meteor(ite) is a pre-existing condition.
> The pieces that are found are > called meteorites, but not the body that is still falling. That is a > meteoroid.
I thought it was a meteoroid when it was orbiting the Sun along with the asteroids and comets, a meteor when it streaked through our atmosphere, and a meteorite when it hit the ground.
On Sun, 8 Nov 2009 09:41:21 -0800 (PST), wsnel...@hotmail.com wrote: >> That is not the usual usage. The reason we consider them meteorites >> while still in the air after ablation is simple: if they survive >> ablation, they will survive impact. Always.
>Not if they don't impact.
I'd like to know how a meteoroid that survives ablation can fail to impact! Where do you think it goes once it's in cold free fall? _________________________________________________
On Sun, 08 Nov 2009 12:39:24 -0500, Davoud <s...@sky.net> wrote: >> An object that survives ablation in the atmosphere is correctly called a >> meteorite while it is falling. So we talk about the dark flight of the >> meteorite, or the aerodynamics of the meteorite as it falls.
>But only by changing its name _after_ it strikes the Earth.
If you were to attend a meteoritics conference, you'd find that "meteorite" is used to describe both an object on the ground, and also an object that is no longer burning; i.e. the object from the time that ablation ends until (and after) it impacts. In fact, you would also commonly find the term "meteorite" used to describe the parent body even while it was in its ablative phase (typically "meteor") if that body ultimately went on to impact. This is just common usage; there is no formally accepted nomenclature for what the body itself is called during its ablative phase. Some use meteoroid, some use meteorite, and the IAU is currently considering defining "meteor" to include both the visible light phenomenon (its current meaning) as well as the body itself during this phase.
>OTOH, if you're at a public event and a meteor streaks through the sky >and Mary Q. says "Wow, did you see that meteorite," and if it's an >educational event, you will tell Mary that it's called a meteor and it >won't be called a meteorite until and unless it strikes the Earth.
That's exactly what I would tell Mary.
>But it seems to me that, since you would not call it a meteorite while >it was only a bright streak in the sky, when you begin to talk about >the meteorite's dark flight or about having seen it streaking toward >you, you are revising its entire history of n billion years -- "this >meteorite probably originated..." Now it was a meteorite from the >moment of its origin. It's Schrödinger's meteor/meteorite.
When the meteoroid is still a meteor, you have no way of knowing if anything will survive (it probably won't). Indeed, if you simply witness a meteor, you have no way of knowing if anything _did_ survive (it probably didn't), so you would have no grounds for calling anything a meteorite. However, when you are holding a meteorite in your hand, then you know for a fact that it survived its ablative phase, and it becomes perfectly correct to refer to it as a meteorite even before it hit (depending somewhat on context). Again, this is just conventional usage, and for the most part not strictly defined. _________________________________________________
On Sun, 8 Nov 2009 13:21:11 -0800 (PST), Quadibloc <jsav...@ecn.ab.ca> wrote:
>I thought it was a meteoroid when it was orbiting the Sun along with >the asteroids and comets, a meteor when it streaked through our >atmosphere, and a meteorite when it hit the ground.
The middle phase isn't formally defined. "Meteor" just refers to the light emitted, not the body producing the light (although the IAU is considering changing this). Some people already just use "meteor" to refer to the body during that phase, and others use "meteoroid". Some use "meteorite" if it is a meteor associated with a known fall (nobody would use that term otherwise, however), and nearly everybody refers to a body that survives ablation as a "meteorite", even before it strikes the ground. The key requirement for "meteorite" isn't actually striking the ground, but surviving ablation and therefore being certain to do so. _________________________________________________
On Sun, 8 Nov 2009 09:38:47 -0800 (PST), wsnel...@hotmail.com wrote: >Definitions can get fuzzy. A meteoroid that enters a planet's >atmosphere on a grazing trajectory, survives ablation and then heads >back out into space without reaching the planet's surface must still >be a meteoroid, not a meteorite.
When I say "survives ablation" I mean that it has stopped ablating while in the atmosphere, and bulk material has survived. Such a body never grazes the atmosphere and reenters space. Clearly nobody would refer to a body that returns to space as being a "meteorite". Of course, grazing bodies of non-cometary origin are very rare. _________________________________________________
On Nov 8, 3:31 pm, Chris L Peterson <c...@alumni.caltech.edu> wrote:
> The middle phase isn't formally defined. "Meteor" just refers to the > light emitted, not the body producing the light (although the IAU is > considering changing this).
Hmm. I guess I just assumed that since "meteor" is the name of the phenomenon, and the phenomenon is the falling object, what else could it name.
While an -oid is a celestial body and an -ite is a mineral, though, calling an object by different names through its career is inherently confusing. It would be simpler to call a meteorite a fallen meteoroid, and a meteor a falling meteoroid.
A thing should have one name. If you want to specify where you are in its history, you can use an adjective.
On Nov 8, 3:13 pm, Chris L Peterson <c...@alumni.caltech.edu> wrote:
> I'd like to know how a meteoroid that survives ablation can fail to > impact! Where do you think it goes once it's in cold free fall?
Perhaps what is envisaged is that what survives ablation impacts, and is turned to dust by the force of that impact, which dust is blown away by the wind, never to be found.
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