Ageeva
Jedi
I was listening to a radio interview today with the author of a newly published book called: INCOMING: or Why We Should Stop Worrying And Learn To Love The Meteorite!. I’ve transcribed the interview below and I find it incredible that the Tunguska event is never mentioned by the author once in the interview. I haven’t read the book yet, it's just out, so there might be a mention of Tunguska in it. But you can tell from the interview and from the subtitle of the book that he is quite dismissive of any imminent danger to the Earth. First this from Amazon:
Product description from Amazon:
Astonishing new research suggests that 470 million years ago, a stupendous collision in the Asteroid Belt (whose debris is still falling today) bombarded the Earth with meteorites of all sizes. A revolutionary idea is emerging that the resulting ecological disturbance may have been responsible for the single greatest increase in biological diversity since the origin of complex life - the hitherto unexplained Great Ordovician Biodiversity Event. Introducing these fresh discoveries to a wider public for the first time, Ted Nield challenges the orthodox view that meteorite strikes are always bad news for life on Earth. He argues that one of the most widely known scientific theories - that dinosaurs were wiped out by a strike 65 million years ago - isn't the whole picture, and that the causes of the end-Cretaceous mass extinction (of which the dinosaurs' demise was a part) were much more varied and complex.
Meteorites have been the stuff of legend throughout human history, interpreted as omens of doom or objects of power. But only in the 18th century, when the study of falling space debris became a science, were meteorites used to unlock the mysteries of our universe. Incoming! traces the history of meteorites from the first recorded strike to the video recordings made routinely today, showing how our interpretations have varied according to the age in which they fell, and how meteorite impacts were given fresh urgency with the advent of the atom bomb. Introducing a wealth of fascinating characters alongside extraordinary new research, Ted Nield has written the perfect introduction to the science and history of the falling sky.
About the Author
Ted Nield holds a doctorate in geology and works for the Geological Society of London as Editor of the monthly magazine Geoscientist. He was Chair of the Association of British Science Writers and is a Goodwill Ambassador for the UN International Year of Planet Earth. He is a Fellow of the Geological Society and a member of the Meteoritical Society. His first book, Supercontinent, was published in 2007. He lives in London.
And the interview: Interviewer is Pat Kenny on Irish National Radio Broadcaster, Radio One
PK: Meteorites have been the stuff of wonder throughout human history, interpreted as omens of doom or objects of power. Scientists have linked the crash of a 10 kilometre wide rock 65 million years ago with the demise of the dinosaurs for example. Since the dawn of Hollywood meteorites are seen as a threat to modern civilisation as they plunge towards Earth. Geologist Ted Nield believes that this is all too much and his latest book: Incoming! Or why we should stop worrying and learn to love the Meteorite', traces the history of those heavenly missiles. And Ted joins me on the line, Ted, good morning!
TN: Good morning!
PK: What would happen if an asteroid hit the Earth?
TN: Well, it would depend how big it was and what part of the Earth it hit, whether it hit land or sea. And, of course, the other thing if you're looking at it in the long term, is the distribution of the continents over the Earth and so on. So it depends really on the context in which these things happen, and that kind of is the message of the book really, that you can't necessarily say if this happens then the consequences will be so and so, because the consequences depend more on the context than they do on the event themselves. Mind you, it would be nasty! (Laughter)
PK: Ok, lets talk about the physics of the thing. The object, this heavenly missile as I put it, is coming towards Earth. I mean, some of them if they were small enough would burn as they came through, and we see them as shooting stars. Would others bounce off the atmosphere and just depart?
TN: Yes...
PK: And you know how big would they have to be to cause us alarm?
TN: Well, of course many do, the Earth actually receives between 30 and 40 thousand tons of meteorites every day, so, as we pass though space on the orbit of the planet we hit space dust all the time. Some of this is big enough to form shooting stars, they're mostly sand and pea-grit kind of size which form shooting stars and burn up inside the atmosphere. Bigger ones? It rather depnds on what they're made of because meteorites can be made of rocky material which tends to be brittle, not very strong, tends to break up in the atmosphere, and iron meteorites which are the remnants of the cores of broken up asteroids, and they are tough enough, if they're big enough, to make it right through to the ground. So there are lots of different dependencies here. Most meteorites that land on the ground are stony in nature and they break up, and they make fireballs, bolides, in the sky, big explosions.
They're very dramatic and they strew a large area with small meteorites, which people then go and try and find so that they can reassemble the original. Those which cause big explosions which could be dangerous or which actually make it through the atmosphere – they have to be a lot bigger and most of them are iron meteorites because they have to tough. You got to remember that meteorites, when they travel through space are travelling at cosmic velocities and these could be 30 to 40 kilometres per second. So, if you've ever jumped into a swimming pool off a high board and done a belly flop you know it's rather like landing on concrete. And it's the same for a meteorite when it hits even the thin atmosphere of the Earth it's going so fast that it's like hitting something solid so it has to be very tough to make it through the atmosphere and hit the ground. And so we are talking about things which are tens to hundreds of metres across and made of iron.
PK: Alright, so they are the dangerous objects. Are we capable of detecting those at any great distance? I mean, how, given the speed, 30 to 40 kilometres per second, how much early warning can we have of something potentially catastrophic?
TN: Well..... it's getting better all the time, and since we've become aware of what happened to the dinosaurs there has been an international initiative to map the skies, to look for these things, so that we can plot their orbits and, using computers, if you have enough data on the orbit, and you need several sightings, several readings of the orbit before that becomes accurate enough, you can then wind the celestial clockwork on for a number of decades, hundreds of years, and you can compute whether or not the Earth is likely to be hit. But of course it is rather a precise thing because scientists have also worked out that actually the meteorite which hit at the end of the Cretaceous period and had a hand in seeing off the dinosaurs, if that had been eight minutes earlier or eight minutes later on its orbit then it wouldn't have hit the Earth. And well, if you believe the meteorite was solely responsible for what happened at the end of Cretaceous, that was the difference between a world dominated by dinosaurs and a world dominated by mammals and us.
PK: You and I would all be called 'Barney' (Laughter), or 'Dino'! (Laughter). Now the point is, when you've got a large object, obviously telescopes and other instruments can detect them, what about those smaller things, those in-betweeners, that if ,for example, they hit London, or Dublin or Chicago, could do quite a lot of damage without necessarily changing the population too much.
TN: Well, yeah, the smaller they are the more difficult they are to see. The other thing is of course that all meteorites and asteroids, meteorites are of course fragments of asteroids, are pretty dark and you're trying to detect these things in the darkness of space. So, it's a very difficult job, and it's done usually by photographs, by comparing one photograph with another to see if something moves and so on. And it's a long laborious job, which has been made easier by computers. Recently scientists were able to observe early quite a large meteorite which landed in Sudan, and they predicted where it would land and were able then to send an expedition to find the bits. That was the first time that had ever been done. So we're getting much better at it. But what this process has done, we now know that we've mapped something like 75 per cent of all Earth crossing asteroids that exist, so the question is should we press on and map all of them. I think we should, it's only sensible. At the moment, what this has achieved for us is to effectively reduce the amount which we have to worry about, because not one of those asteroids which have been found is on a collision course with Earth, and none of them is likely to hit the Earth in the foreseeable future.
PK: So, they've done the odds, they've calculated the odds. In comparison with other risks that we routinely involve ourselves in what is the risk of us being hit by somethig significant?
TN: Well the global risk of death by asteroid – now this is the global risk so it is globalised for the whole population of the Earth. The global risk of dying in an aircraft accident which includes all those people who live in the jungles of Borneo and who would never go into an airport in their lives. So normalised for the whole poplulation of the Earth, the chances of dying by asteroid are estimated at 1 in 700.000. Which is about the same as the risk of dying by firework! (Laughter). We live with that. Even on Guy Fawkes night! (Laughter)
PK: So, for example other risks, say the risk of dying in an aircraft crash, a motor accident, or say an earthquake?
TN: Yes, by comparison they are orders of magnitude more likely. Even if they are more likely they are 1 in tens of thousands for those sorts of natural disasters and when you're talking then about the really important risks which is like the risk of being squashed by a bus, the risk of a car accident – those risks are by comparison, well I was going to say astronomical! (Laughter)
PK: Is the jury in any way still out on the dinosaurs? I mean, are we certain it was a massive heavenly body that did it for them?
TN: We're certain there was a massive impact at the end of the Cretaceous. There are other things which are less certain. It's my belief, and it's many geologists' belief that you cannot ascribe something like a mass extinction to single causes. And life at the end of the Cretaceous was having a really terrible time. It was an awful time to be alive. And one of the many things at the end of the Cretaceous that helped things on their way to oblivion was a massive meteorite strike. Of the five major mass extinctions that we know about only that one has been connected with any sort of extraterrestrial cause – all of the others happened at the same time, for example, as massive vulcanism on a scale which our species has just never witnessed and, with any luck, never will, called the Large Igneous Province eruption, and the one at the end of the Cretaceous was happening in India at the time. It created the Deccan traps, and it happened right at the end of the Cretaceous so that was another thing going on then that helped to kill the dinosaurs off. In other words I think that the dinosaurs would probably not be here anyway. The asteroid, in a sense,was just the straw that broke T-Rex's back! (Laughter)
PK: You argue that the meteorite, if one happens to land, can actually enrich the Earth's ecology. What's the theory of that?
TN: Ah, that's the most recent piece of science which I include in the book, and it's the reason for, if you take the long view, looking in a more kindly way upon meteroites. It appears that 480 millions years ago, which is a very long time ago in the mid Ordovician, we now know that the Earth was peppered with meteorites such that the meteorite flux, the daily load of meteorites that lands every day, went up by a 150 fold for about 10 million years. Now that was the result of a collision in the asteroid belt and there were so many meteorites falling at the time that geologists have actually been finding fossilised meteorites which must be the rarest possible thing that you could possilby have. So here are these usually very rare events becoming so common that they even survive all the processes of fossilisation and 480 million years of erosion and they find them in such large quantities. So we know there was this massive increase in bombardment at that time.
And it just so happens that paleontologists, looking at rates of extinction and looking at rates of speciation through the fossil record hac noticed that at this time, the middle Ordovician, was one of incredible diversity increase for which there was no known explanation. It's the biggest biodiversification event in the whole of the known fossil record and it had no apparent cause. It was not a rebound after a mass extinction for example. It was just a great mystery. Until this discovery in Sweden by Professor Berger Schmits of Lund University and a predecessor of his called Per Thorsland, when they started finding these meteorites they found that perhaps there was a connection between these two things because maybe the bombardment somehow delivered what you might call 'a kick in the genes' to life! (Laughter)
PK: Ok, we have a couple of questions coming in from our listeners and the first one is, well it's a statement: 'Only one person has being known to have been killed by an asteroid or a meteorite, that was in Tung..suska (sic) in Siberia in 1908, that's from Peter in Cork'. Is that so?
TN: Yes, and that's.... well officially there are no known victims of meteorites. Plenty of people have been hit by them but all the supposed known records of people who have been killed by them are in some way dubious. They are either so ancient or they are hearsay.
PK: So let us not worry about that possibility.
TN: Yeah, that's right.
PK: And the other question is, 'What about an asteroid deterrent? Can we shoot them down, break them up, as Hollywood would suggest or even hit them with something large to divert them out of their Earth bound orbit?
TN: Well the thing about asteroids, there are science fiction scenarios which we could employ. Hollywood always talks about putting a big bomb in and blowing them up and that's because of dramatic necessity. You have to have a big bang in a blockbuster movie and you would have to do it with a bomb. It would be a very silly thing to do because if there was a big asteroid heading towards you all you would do is create a small asteroid family heading towards you so instead of one big impact you may have several still very big impacts which would not be.. terrific. But there is a much less dramatic scenario and that is that if you did see an asteroid in an Earth crossing orbit, which you calculated in maybe a number of decades, which might hit the Earth with a fair degree of certainty, you could conceivably attach to it a small motor, an engine, iron engine of some sort, which would gradually over many many orbits cause the orbit to change, by thrusting it very gently in another direction....
PK: And even with the smallest change it would miss us because we're tiny?
TN: It would miss us yes. That's right.
PK: One last thing, based on what you said Ted, the Earth is getting heavier all the time, every day. This stuff is landing on us!
TN: Yes. It's growing by tens of thousands of tons every year but the Earth is so enormous it doesn't make any difference at all.
PK: Well, the book is fascinating. It's called: 'INCOMING! Or Why We Should Stop Worrying And Learn To Love The Meteorite'. It's publlished by Grant books, 26.50 in hardback and the author, Ted Nield. Thank you very much for joining us on the programme this morning!
TN: Great pleasure!
---------------------------------------------
I wonder if the PTB are behind this, to counter something that might be circulating on, well, SOTT? Or maybe I'm just being paranoid ;)
Product description from Amazon:
Astonishing new research suggests that 470 million years ago, a stupendous collision in the Asteroid Belt (whose debris is still falling today) bombarded the Earth with meteorites of all sizes. A revolutionary idea is emerging that the resulting ecological disturbance may have been responsible for the single greatest increase in biological diversity since the origin of complex life - the hitherto unexplained Great Ordovician Biodiversity Event. Introducing these fresh discoveries to a wider public for the first time, Ted Nield challenges the orthodox view that meteorite strikes are always bad news for life on Earth. He argues that one of the most widely known scientific theories - that dinosaurs were wiped out by a strike 65 million years ago - isn't the whole picture, and that the causes of the end-Cretaceous mass extinction (of which the dinosaurs' demise was a part) were much more varied and complex.
Meteorites have been the stuff of legend throughout human history, interpreted as omens of doom or objects of power. But only in the 18th century, when the study of falling space debris became a science, were meteorites used to unlock the mysteries of our universe. Incoming! traces the history of meteorites from the first recorded strike to the video recordings made routinely today, showing how our interpretations have varied according to the age in which they fell, and how meteorite impacts were given fresh urgency with the advent of the atom bomb. Introducing a wealth of fascinating characters alongside extraordinary new research, Ted Nield has written the perfect introduction to the science and history of the falling sky.
About the Author
Ted Nield holds a doctorate in geology and works for the Geological Society of London as Editor of the monthly magazine Geoscientist. He was Chair of the Association of British Science Writers and is a Goodwill Ambassador for the UN International Year of Planet Earth. He is a Fellow of the Geological Society and a member of the Meteoritical Society. His first book, Supercontinent, was published in 2007. He lives in London.
And the interview: Interviewer is Pat Kenny on Irish National Radio Broadcaster, Radio One
PK: Meteorites have been the stuff of wonder throughout human history, interpreted as omens of doom or objects of power. Scientists have linked the crash of a 10 kilometre wide rock 65 million years ago with the demise of the dinosaurs for example. Since the dawn of Hollywood meteorites are seen as a threat to modern civilisation as they plunge towards Earth. Geologist Ted Nield believes that this is all too much and his latest book: Incoming! Or why we should stop worrying and learn to love the Meteorite', traces the history of those heavenly missiles. And Ted joins me on the line, Ted, good morning!
TN: Good morning!
PK: What would happen if an asteroid hit the Earth?
TN: Well, it would depend how big it was and what part of the Earth it hit, whether it hit land or sea. And, of course, the other thing if you're looking at it in the long term, is the distribution of the continents over the Earth and so on. So it depends really on the context in which these things happen, and that kind of is the message of the book really, that you can't necessarily say if this happens then the consequences will be so and so, because the consequences depend more on the context than they do on the event themselves. Mind you, it would be nasty! (Laughter)
PK: Ok, lets talk about the physics of the thing. The object, this heavenly missile as I put it, is coming towards Earth. I mean, some of them if they were small enough would burn as they came through, and we see them as shooting stars. Would others bounce off the atmosphere and just depart?
TN: Yes...
PK: And you know how big would they have to be to cause us alarm?
TN: Well, of course many do, the Earth actually receives between 30 and 40 thousand tons of meteorites every day, so, as we pass though space on the orbit of the planet we hit space dust all the time. Some of this is big enough to form shooting stars, they're mostly sand and pea-grit kind of size which form shooting stars and burn up inside the atmosphere. Bigger ones? It rather depnds on what they're made of because meteorites can be made of rocky material which tends to be brittle, not very strong, tends to break up in the atmosphere, and iron meteorites which are the remnants of the cores of broken up asteroids, and they are tough enough, if they're big enough, to make it right through to the ground. So there are lots of different dependencies here. Most meteorites that land on the ground are stony in nature and they break up, and they make fireballs, bolides, in the sky, big explosions.
They're very dramatic and they strew a large area with small meteorites, which people then go and try and find so that they can reassemble the original. Those which cause big explosions which could be dangerous or which actually make it through the atmosphere – they have to be a lot bigger and most of them are iron meteorites because they have to tough. You got to remember that meteorites, when they travel through space are travelling at cosmic velocities and these could be 30 to 40 kilometres per second. So, if you've ever jumped into a swimming pool off a high board and done a belly flop you know it's rather like landing on concrete. And it's the same for a meteorite when it hits even the thin atmosphere of the Earth it's going so fast that it's like hitting something solid so it has to be very tough to make it through the atmosphere and hit the ground. And so we are talking about things which are tens to hundreds of metres across and made of iron.
PK: Alright, so they are the dangerous objects. Are we capable of detecting those at any great distance? I mean, how, given the speed, 30 to 40 kilometres per second, how much early warning can we have of something potentially catastrophic?
TN: Well..... it's getting better all the time, and since we've become aware of what happened to the dinosaurs there has been an international initiative to map the skies, to look for these things, so that we can plot their orbits and, using computers, if you have enough data on the orbit, and you need several sightings, several readings of the orbit before that becomes accurate enough, you can then wind the celestial clockwork on for a number of decades, hundreds of years, and you can compute whether or not the Earth is likely to be hit. But of course it is rather a precise thing because scientists have also worked out that actually the meteorite which hit at the end of the Cretaceous period and had a hand in seeing off the dinosaurs, if that had been eight minutes earlier or eight minutes later on its orbit then it wouldn't have hit the Earth. And well, if you believe the meteorite was solely responsible for what happened at the end of Cretaceous, that was the difference between a world dominated by dinosaurs and a world dominated by mammals and us.
PK: You and I would all be called 'Barney' (Laughter), or 'Dino'! (Laughter). Now the point is, when you've got a large object, obviously telescopes and other instruments can detect them, what about those smaller things, those in-betweeners, that if ,for example, they hit London, or Dublin or Chicago, could do quite a lot of damage without necessarily changing the population too much.
TN: Well, yeah, the smaller they are the more difficult they are to see. The other thing is of course that all meteorites and asteroids, meteorites are of course fragments of asteroids, are pretty dark and you're trying to detect these things in the darkness of space. So, it's a very difficult job, and it's done usually by photographs, by comparing one photograph with another to see if something moves and so on. And it's a long laborious job, which has been made easier by computers. Recently scientists were able to observe early quite a large meteorite which landed in Sudan, and they predicted where it would land and were able then to send an expedition to find the bits. That was the first time that had ever been done. So we're getting much better at it. But what this process has done, we now know that we've mapped something like 75 per cent of all Earth crossing asteroids that exist, so the question is should we press on and map all of them. I think we should, it's only sensible. At the moment, what this has achieved for us is to effectively reduce the amount which we have to worry about, because not one of those asteroids which have been found is on a collision course with Earth, and none of them is likely to hit the Earth in the foreseeable future.
PK: So, they've done the odds, they've calculated the odds. In comparison with other risks that we routinely involve ourselves in what is the risk of us being hit by somethig significant?
TN: Well the global risk of death by asteroid – now this is the global risk so it is globalised for the whole population of the Earth. The global risk of dying in an aircraft accident which includes all those people who live in the jungles of Borneo and who would never go into an airport in their lives. So normalised for the whole poplulation of the Earth, the chances of dying by asteroid are estimated at 1 in 700.000. Which is about the same as the risk of dying by firework! (Laughter). We live with that. Even on Guy Fawkes night! (Laughter)
PK: So, for example other risks, say the risk of dying in an aircraft crash, a motor accident, or say an earthquake?
TN: Yes, by comparison they are orders of magnitude more likely. Even if they are more likely they are 1 in tens of thousands for those sorts of natural disasters and when you're talking then about the really important risks which is like the risk of being squashed by a bus, the risk of a car accident – those risks are by comparison, well I was going to say astronomical! (Laughter)
PK: Is the jury in any way still out on the dinosaurs? I mean, are we certain it was a massive heavenly body that did it for them?
TN: We're certain there was a massive impact at the end of the Cretaceous. There are other things which are less certain. It's my belief, and it's many geologists' belief that you cannot ascribe something like a mass extinction to single causes. And life at the end of the Cretaceous was having a really terrible time. It was an awful time to be alive. And one of the many things at the end of the Cretaceous that helped things on their way to oblivion was a massive meteorite strike. Of the five major mass extinctions that we know about only that one has been connected with any sort of extraterrestrial cause – all of the others happened at the same time, for example, as massive vulcanism on a scale which our species has just never witnessed and, with any luck, never will, called the Large Igneous Province eruption, and the one at the end of the Cretaceous was happening in India at the time. It created the Deccan traps, and it happened right at the end of the Cretaceous so that was another thing going on then that helped to kill the dinosaurs off. In other words I think that the dinosaurs would probably not be here anyway. The asteroid, in a sense,was just the straw that broke T-Rex's back! (Laughter)
PK: You argue that the meteorite, if one happens to land, can actually enrich the Earth's ecology. What's the theory of that?
TN: Ah, that's the most recent piece of science which I include in the book, and it's the reason for, if you take the long view, looking in a more kindly way upon meteroites. It appears that 480 millions years ago, which is a very long time ago in the mid Ordovician, we now know that the Earth was peppered with meteorites such that the meteorite flux, the daily load of meteorites that lands every day, went up by a 150 fold for about 10 million years. Now that was the result of a collision in the asteroid belt and there were so many meteorites falling at the time that geologists have actually been finding fossilised meteorites which must be the rarest possible thing that you could possilby have. So here are these usually very rare events becoming so common that they even survive all the processes of fossilisation and 480 million years of erosion and they find them in such large quantities. So we know there was this massive increase in bombardment at that time.
And it just so happens that paleontologists, looking at rates of extinction and looking at rates of speciation through the fossil record hac noticed that at this time, the middle Ordovician, was one of incredible diversity increase for which there was no known explanation. It's the biggest biodiversification event in the whole of the known fossil record and it had no apparent cause. It was not a rebound after a mass extinction for example. It was just a great mystery. Until this discovery in Sweden by Professor Berger Schmits of Lund University and a predecessor of his called Per Thorsland, when they started finding these meteorites they found that perhaps there was a connection between these two things because maybe the bombardment somehow delivered what you might call 'a kick in the genes' to life! (Laughter)
PK: Ok, we have a couple of questions coming in from our listeners and the first one is, well it's a statement: 'Only one person has being known to have been killed by an asteroid or a meteorite, that was in Tung..suska (sic) in Siberia in 1908, that's from Peter in Cork'. Is that so?
TN: Yes, and that's.... well officially there are no known victims of meteorites. Plenty of people have been hit by them but all the supposed known records of people who have been killed by them are in some way dubious. They are either so ancient or they are hearsay.
PK: So let us not worry about that possibility.
TN: Yeah, that's right.
PK: And the other question is, 'What about an asteroid deterrent? Can we shoot them down, break them up, as Hollywood would suggest or even hit them with something large to divert them out of their Earth bound orbit?
TN: Well the thing about asteroids, there are science fiction scenarios which we could employ. Hollywood always talks about putting a big bomb in and blowing them up and that's because of dramatic necessity. You have to have a big bang in a blockbuster movie and you would have to do it with a bomb. It would be a very silly thing to do because if there was a big asteroid heading towards you all you would do is create a small asteroid family heading towards you so instead of one big impact you may have several still very big impacts which would not be.. terrific. But there is a much less dramatic scenario and that is that if you did see an asteroid in an Earth crossing orbit, which you calculated in maybe a number of decades, which might hit the Earth with a fair degree of certainty, you could conceivably attach to it a small motor, an engine, iron engine of some sort, which would gradually over many many orbits cause the orbit to change, by thrusting it very gently in another direction....
PK: And even with the smallest change it would miss us because we're tiny?
TN: It would miss us yes. That's right.
PK: One last thing, based on what you said Ted, the Earth is getting heavier all the time, every day. This stuff is landing on us!
TN: Yes. It's growing by tens of thousands of tons every year but the Earth is so enormous it doesn't make any difference at all.
PK: Well, the book is fascinating. It's called: 'INCOMING! Or Why We Should Stop Worrying And Learn To Love The Meteorite'. It's publlished by Grant books, 26.50 in hardback and the author, Ted Nield. Thank you very much for joining us on the programme this morning!
TN: Great pleasure!
---------------------------------------------
I wonder if the PTB are behind this, to counter something that might be circulating on, well, SOTT? Or maybe I'm just being paranoid ;)
