About science; About meteorites

This is about science produced by the California Institute of Technology and originally broadcast by station KPCC in Pasadena California. The programs are made available to this station by national educational radio. This program is about media rights with host Dr. Albert here and his guest Dr. Irene Goddard of the Kel-Tec geochemistry Department. Here now is Dr. hit throughout recorded history meteorites held a place of special mystery and it's very likely that man discovered iron first in the form of meteorites. As a matter of fact some languages show this by the similarity of the words that they use for iron and star. And now although we certainly know a considerable amount about meteorites more than we did then we still have a few mysteries that hadn't quite been dispelled. And to tell us about some of the new research on the nature of meteorites as well as some of the old stories that have followed them through the years we have as our guest Irene Goddard of the chemistry department at Caltech. Mary let me start out by going back to some of these old

tales. Was it always pretty much under. We're heavenly phenomenon come from the sky. Yes I think that there was no question through the ancients that they did come from the skies they saw them and they accepted without and considered to be gifts from the dogs or some sort of miraculously information they call iron iron from heaven. For example he did that in Egyptian ancient Egyptians called an idol from heaven and the Greeks were thriving. See there are those which are similar to consider I mean Star which means. So there was a definite connection always lying between the origin

days wasn't other than much for quite a while. Then first startle was the one that question when he suggested that there probably were aerial phenomena. These are just the media which can really air now the day I thought they were connected with the Stars and then have a controversy right. And then a few lonely voices every now and then Such as part of the sixteenth century was quite convinced that the Stones may descend from heaven except that no one decent thing and that's because the Middle Ages people still thought that they were from heaven but that they were signs of God's anger but they had a religious meaning throughout as well obviously as the company. And so then when the Enlightenment period came when the emphasis was very much and the empirical method and since most scientists

certainly are not the witness here I completely discounted all reports even those that were there well substantiated. Also the change was not to reject religious or mythological it was to reject the whole idea and many people such as the famous French chemist lead was actually to analyze your idea of loosing it which is known to be founded to be a pyrite which is a terrestrial rock and from that Paris signed a memorandum which concluded that stones are supposedly cosmic origin were ordinary trail rocks struck by lightning and that the falling of stones from the skies physically. This sounds a little bit of a pronouncement of thought very unscientific

group even today. Exactly and the unfortunate thing is that then that carries if the authorities are impressive enough then they carry with them a lot of other Sankyo just who get on the bandwagon. And so there were a whole series who even right before the eyes of the skin of the mayor and the whole city council. What contract you know any and recorded in the city records and then there could lend other friends thank you. Said how sad it is that in time and supposedly he enters folktales upon official records presenting them as something actually seen while they cannot be explained by physics nor by anything reasonable. And so this continues for quite a while and even into the 19th century even go by the turn of the century thanks to one particular physicist

who had enough courage to go against the current and did write a book explaining their reasonable fashion how he would come from. Could we explain what exactly. Even then. So some scientists already believe that but in 18 0 7 for example a stronger eye chart on your western Connecticut and was extensively described by Professor Kingsley in Salem and of Yale President Thomas Jefferson. Her this is reported to have commented that he found it easier to believe that Yankee professors would lie than that stones would fall from heaven. What is the difference between a meteor or a meteorite.

For practical purposes we use the definition is something that is a shooting star that makes a flash in the sky and your eye is something large enough to pass through the atmosphere not burn up and reach the ground as a large enough chunk so it can be found in for example and I'm not the only difference between them. Actually you know because the media or sort of two arises at least in their behavior. There are some that are periodic becoming swarms at certain times of the year which means that the earth goes round sending its orbit once a year crosses runs and we are Stream the returning showers and they most likely are the debris of comet Sousa's what's left over. Comet from

Comet had to migrate after going around exactly and then gradually get dissipated and this is why the showers from year to year. My exact position on the origins and then the other hand there are sporadic so-called sporadic movie or that just appear with random and those may well have the same origin as meteorite was here today are smaller and are nothing yet. So clearly them from these two kinds of behavior must be at least two origins. Two things. When and how often does a meteorite one that is big enough to hit the ground a novel of this happen if you go to to say definitely because the earth is covered by water. Such a large extent and in of course some of the areas are still unhappy with no calculating from

the most densely populated areas such as Japan and valley inordinately where especially many falls have been reported. Mainly because there are some people around who would through them and other theoretical considerations brownness calculated that there are probably about five hundred sixty dollars a year all or all of the earth. Right so they are then dividing it. It would be one point one falls per year for one million kilometers squared. An area of 1000 and I feel about 600 miles square and you get about one near right big enough to pick up right of course. This this is just an average and naturally they don't even be distributed. Suppose big ones or much more really big ones. It's estimated again that it's probably every few hundred years

that the large one falls. And that's a large one such as the Russian meteorite shower which so I believe in one thing for the cinema or thereabouts and it was several cons were of material were collected and it was called calculated that several hundred pounds may have been evaporated during the flood because a large mass and therefore tremendous energy would be converted to vapor and this is the reason that sometimes these very large meteorite craters of which there are a number identified by now. Incidentally it has only been 60 years since it was first suggested that meteorites may make craters. And so more and more discovered as being an origin finally allowed to be thought of. What exactly are they better about

coming in the AB lies another fact been named in Spanish means the Devil's Canyon. Or was this recognize Well you've had it through legends I suppose that a fiery God had descended from this kind that spot. How long ago was a and with estimated it was five thousand years at the law. Girl what would not have been a very impressive sight for example something as big as the struggle on the ledge of a well and then there are other series of craters in Australia which are estimated to be only about a thousand years old and young Australian Aborigines have a name for it and that sort of a combination of words. Sky devil still I see and that whole area is still going and so they also read exactly

what happened. I suppose that actually very few of these are seen as they for most of them must be picked up at some later time is there any estimate of how many are picked up right away sort of hot out of the sky. How many are found at some later time. As a matter of fact one of the bronze graduate former graduate students that can be not such a calculation using a private catalogue which was a very good catalog that included flowers and signs and you can find all I write is you crying I guess this must mean to you if you want to back up and the ones that later on you can eat you grinding thing it looks strange and you think it's in Lang's identified to be in the right. He did I did. The years are making hundred nine hundred fifty three

year periods. And we found that in the period from making hundred fifty six to seven percent of falls were reported within five years which is quite remarkable. It was only at the turn of that century that they decided and then within the next ten years an additional six percent were sorted and then next thing again for more percents it was 77 percent are reported after 20 years and then 30 years a few percent in 50 years 92 percent reported. Now how does you know that not all of them reported it because some were seem to fall and then were picked up and I think I was meteorites but they were never recovered. For example to go back to this Enlightenment period the pressure was so hard that you know to be identified with the people on the right side and not the superstitious ones that they're all just born with this

name. Vienna where he had already started a pretty little collection was called the Imperial collection of all kinds of things. And among them were a lot of their rights. And he was afraid that his reputation was at stake that he was collecting silly things and so he threw them all out. And so they were recorded and then could never be recreated. Then as we go on we find that from 100 1950 it within the first five years the 1 percent get reported in the next 10 years. It comes to eighty six. Within 20 years 95 percent reported for his first five years at that category. The ones that were actually seen before. The person who found them just didn't go in and you know you know where he is this is a very important factor.

And well very critical actually because it has been estimated the United States only one knew me here right here and gets into the hands of scientists who are going to get their hands on it. Before we want to further let me ask you then someone should find see immediately or can find a meteorite meteorite or go out and find it. What you can do is advance the cause of ticks. Fortunately there are few places where you could. Write soon and tell them about it and this thing could be identified without being charged. One is the Smithsonian Institution Astrophysical Observatory in Cambridge Massachusetts. It was the right and the person to write to Dr F. L. Whipple HIPPA

Dr. Whipple of the Smithsonian astronomical writer or Dr. E.P. Henderson who is curator of neurology and pathology at the US National Museum in Washington for the US National Museum in Washington Dr. Henderson. Dr. Whipple at the Smithsonian and Cambridge going in by the United States. The person on whose property right is the legal owner of it. You know other countries going on this was of any value to letting it lie there and speaking it out and somebody come down and ground around it and see if it's only for a very short time. On one hand yes it would but actually perhaps it would be better to take a picture of it in place before taking it out because one reason that some weaker eyes it's important to get them very quickly is because

they have been doing studies of some of the radioactive isotopes which would kill about their cause make great exposure ages because Iraq is running far. Yes because also if there are fragments then different ones have been found to have different ages for instance respect and some of the isotopes have short lives. So insulated one waits then at least that part is somewhat lost completely. To get them out you are sadly. So one should take pictures. Of course if you actually see it for every little detail that one can possibly remember is very important and we should write it all down immediately afterward because it's very easy to forget things one time as another fact. From the point of view of our research that time is extremely important and

so I would even suggest that one check of the personal watch with it with the telephone time or something like that because it can be that important and one should remember and it has been suggested and I think it's a very good idea to make a sketch because very often if the idea is large enough it will appear as a boy allied as a big fireball in the night sky and will make a trail of sometimes chunks of it break off and fall and all these things will be noted in the record and you could be then good to make a sketch with people have joined. Exactly there because it's very difficult to kill the orbits of asteroids. Usually people that do happen to see them are not trained observers. So you're work is looking up the orbit of a meteorite. Yes Dr Ron I did one study. The frequency of me here I because for quite

some time it was known that they do seem to fall not quite evenly at random but they come in cycles. There seem to be and maxima and minima for example there are seasonal variations one in about March and another in mid summer and just variations of people finding them or something that of course we have to consider. And it was found that even though it certainly does have some in France for example in Europe if you look at the days of the week fewer falls like by about 30 or 40 percent fewer hours are recorded on Sundays because people working in the field and the other hand. And then then Coop the sort of area is very important because

for example in India although there were very many rights reported that a very large completely out of the ordinary proportion of them were false. Because he is very dense vegetation and so forth were in Chile they were all about 30 or 40 and none of them were seeing that because of dry baking and yes they can easily be seen and because it's dry they they are preserved longer and this is another important point of these two major categories. There are two very distinct classes. Some are made almost entirely of iron nickel and others are stirring. I feel that I am one of the ones you hear about most of the time a famous Army are these the commonest known as another fact most of the faults that are seen. Of the other type going at this telling me. But the

irony here I'm easier to identify. They often very look very impressive because they're very very heavy and this is why it's much easier to identify one when you find one and sometimes they look black and they have so like fingerprints like even patients made by some. Which is because a male thing while they're flying through has played only once a local disco anyone sometimes may look like an ordinary rock very different and spot exactly. Much larger proportion of the finds are irons and was larger proportion of the falls are Congress but it's thought that probably they are 50/50. See this is not definite because again we just don't have enough data but the analysis of when they fall and where they come from does indicate that there is a lot of this variation from this concentration in the spring and late summer as a real concentration.

Yes not only that when we looked at different causes in your eyes for instance among these ones there are two again very distinct classes which we can call low iron high iron nickel iron even in the stone Oh yes throughout the old and have some. And so when we looked at these two different one separately it seems that some of the knocks you know some of the peaks. Our due to the high iron variety and others to the low iron so the switch is very important because it would suggest that they do behave slightly differently. The Pacific grouping of act to be nominal rather than exact observation. And then when we look at longer periods for example like five year period seems to have a very high peak and this is to be expected if indeed there should be a right stream to which the earth then would pass every year like through a comet.

However if they neither ice within their orbit are not distributed evenly all around but are in clusters and only every now and then will we again come to the same spot for the cost. And there seems to be sending that to what I mean if meteorites move in orbits like this it sounds very much like the orbits of asteroids is there a connection. There seems to be very definite connection and the great majority of students and guys believe that they come from the asteroid belt but of course concentrated mostly between Mars and Jupiter a long way from here. Yes except that because Jupiter has such a large mass it perturbs the orbit of asteroids and every now and then one will stray far enough. So that it may approach Earth.

Actually there are several large ones that we're limited again until we can go out in space and look at the belt itself by a what we can see with a telescope and that very often the orbits are very eccentric and during the day if you got to see them because they're not very large but there are several who do approach the earth fairly close I believe there is one that is coming next year. But the calculation in the more observations you have of of an asteroid the more occasions the more careful you can calculate the orbit. And because these are seen each time there are new calculations made recently that Dr Herrick from UCLA had done the calculations and announced it would be about million miles or so. The distances were used between the planets.

But it must be very difficult to get the orbits of meteorites while you feel the tail end of the come extremely difficult and as another the only one that has been carefully calculated was one of those the VIKKY had quite recently in forty something happened if your cameras were photographing the sky not just by a precise accusation 40 kilometers apart. They both photographed it and so it was possible to calculate it well and it turned out to have an asteroid will orbit so at least in the one case we are doing good there is another one in the shower that very large shower in Eastern Siberia and I think of a Russian. Calculated the trajectory from very many reports the shower was so large if people had seen it over a large area and so by projecting what they

thought their actions if they had been within that yes and again he gets a sort of asteroidal Orban if someone is interested in following up the study of his own becoming a hundred other than a good reference with any books that give a good background it was business as well. Amateur meteorite hunter could make use of for a beginning. I would suggest two paperbacks. They're fairly recent certainly recent enough to be correct and one is by lecturer g what is called Between the planet. This talks about asteroids. I think your comment last week that the whole bit is a translation of an excellent book called right by Free translation.

So between the planets by walk from meteorites by Heidi H. About the second one I'd concentrate on the meteor right. Is there any simple way that a person could recognize a meteorite. Very often they have fusion crust black fusion crust that the that happens during their flight through the atmosphere because they do get very hot and the outside layer becomes the work of strong as well as for the arm. Well the irony is easier to recognize because they're very heavy and black and have a little indentation right. And then they have other characteristic things like granules is something that doesn't occur in Crest Trail rocks small

nodules less than three millimeters in diameter and they're made of silicate materials so that they look sort of like little be imbedded in this. It is and you know I got arrested for that and said that one of them breaks thinking seeing a fracture surface. You could go to your sentencing see iron particles and you know the indication that this thing is a meteorite or a course of see one fall and you can make any notes at all about the path streak across the sky. Exactly or any humans who have a lot of things like not meteorite watchers are going to have Jerry thinking this was about science with host Dr. Albert kids and his guest Dr. Irene Goddard of the geochemistry department at the California Institute of Technology. Join us again for

our next program when two more members of the Cal Tech faculty will discuss this object of interest about science is produced by the California Institute of Technology and is originally broadcast by station KPCC in Pasadena California. The programs are made available to the station by national educational radio. This is the national educational radio network.