Meteorites are pieces of rock – usually stone, sometimes metal and,
occasionally, a mixture of both – which find their way to Earth from the
asteroid belt, Mars, the Moon and, possibly, a few comets. They typically
weigh a couple of kilograms (though this can vary tremendously) and strike
the Earth with velocities usually in the range of 100 to 250 metres per
second. The Middlesbrough meteorite, for example, which landed on 14 March
1881, had a terminal velocity of 126 metres per second and weighed about 1.6
kilograms. Fortunately, it did little damage but had anyone been unfortunate
enough to get in its way they would not have lived to tell the tale.

The first recorded fatalities occurred in 616 BC when stony meteorites were
said to have crashed into chariots killing 10 men. Two monks have been
struck by meteorites: one in Cremona in 1511 and the other in Milan in 1650.
In 1674 meteorites killed two Swedish sailors aboard ship. There are also
reports of a wedding guest being killed in one of the Balkan states, and a
child in Japan. Few such reports are well documented, and they may well be
little more than stories.

Undoubtedly, people have had narrow escapes. On 14 July 1847 a 17-kilogram
meteorite fell into a bedroom in which three children were asleep in
Braunau, in what is now Austria. Although they were covered in debris, none
was seriously hurt. Not so lucky was Mrs Hewlett Hodges of Sylacauga,
Alabama, who was hit by a malevolent meteorite on 30 November 1954 causing
severe hip and abdominal injuries.

There are also accounts of animal deaths. A colt in New Concord, Ohio,
perished when about 30 meteorites fell on 1 May 1860, several cows were
killed when a shower of stones hit Macau in Brazil on 11 November 1836, and
on 28 June 1911, 40 stones fell at Nakhla in Egypt killing a dog. The Nakhla
meteorite is only one of a handful of specimens that originated on Mars. To
this day the Nakhla dog remains the only authenticated case of an Earthling
being killed by a Martian.

Fatalities aside, meteorites – even small ones – can cause considerable
damage to anything they hit. Returning to Milan, there is the case of a
red-hot meteorite landing in the castle on 23 June 1525, setting fire to the
munitions. Perhaps not surprisingly, nothing remains of the meteorite.

About half of all meteorites break up in the atmosphere thus increasing the
chances of someone, or something, being hit. But anyone who thinks that
meteorite falls are more or less evenly distributed over the Earth’s surface
will find that the inhabitants of the small town of Wethersfield,
Connecticut, probably disagree with them.

In 1987 Roy Clarke, a well-known meteoriticist, presented a paper to the
50th meeting of the Meteoritical Society on his team’s investigations of the
fall of some 39 meteorites in the US between 1932 and 1982. The team was
prompted to look at the damaging meteorites after two falls in the small
town of Wethersfield. On 8 April 1971, a 350-gram meteorite passed through
the roof of a house and landed in the living room. Eleven years later, on
8 November 1982, a second meteorite of 2.7 kilograms struck another house
only 2.7 kilometres from the first. On both occasions the fire service was
called and, if local reports are true, each time the same fireman found the
meteorite.

In case you are thinking that these two meteorites might have been related
in some way, they apparently had quite different histories. The
meteoriticists could tell that from the extent to which the meteorites were
shocked. Isotope analyses showed that while the first fall had separated
from its parent body about 3 million years ago, the second object became
detached about 50 million years ago.

Since Clarke’s report, one of the most celebrated meteorites is the
Peekskill meteorite, named after the suburb of New York in which it fell
last October. The 10-kilogram stone plunged straight through the boot of a
Chevy Malibu, turning the driveway underneath into a crater. Fortunately,
the owner of the car, 18-year-old high school student Michelle Knapp, was
not in the vehicle at the time. Unperturbed by her near miss, and in the
true spirit of American free enterprise, she sold the $100
second-hand car, and the meteorite, to consortium led by Marlin Cilz of the
Montana Meteorite Laboratory. Cilz will not say how much he paid for the
meteorite, just that the price was very high. As for Knapp, she now has a
decent runaround.

Quite clearly, as towns and cities expand, and as the world’s population
increases, the chances of a meteorite striking a person or some kind of
artefact are going to increase.

All these cases involve quite small meteorites. Occasionally, however, an
asteroid-sized body does strike our planet. The most famous incident in
living memory happened in Siberia on 30 June 1908, when a brilliant
fireball, said to be as bright as the Sun, swept across the skies of Russia
and exploded 8 kilometres above Tunguska. The shock wave flattened 2200
square kilometres of dense forest and travelled around the world several
times. The portable huts of the Tungus nomads were blown over, about 1000
reindeer were killed in the resulting stampede, and at the Vanovara factory,
60 kilometres from the explosion, doors were lifted from their hinges,
windows shattered and pictures fell from walls. Experts still disagree
whether the object was a comet or an asteroid (see New ÐÓ°ÉÔ­´´, Science,
16 January) but one thing is for certain, if such an object ever explodes
over a densely populated city such as London, Edinburgh or Birmingham it
will be a disaster of immense proportions.

Tunguska-size impacts are, fortunately, rare but are probably more common
than experts would have believed just a few years ago. We now have a better
understanding of the sort of objects, and how many there are, that linger in
space near the Earth’s orbit. So, although the object that struck Tunguska
was large and destructive, there are numerous other bodies out there that
are bigger and, potentially, more catastrophic.

I can well remember sitting in a geology lecture ten years ago, shortly
after Walter and Luis Alvarez had announced that the dinosaurs had been
wiped out by a massive asteroidal impact. As with all ‘new’ theories, very
few of those present had read the Alvarez’s paper or, if they had, they
failed to understand that massive impacts could bring about a so-called
‘nuclear winter’. The jokes started to fly and one student asked the
lecturer how some creatures managed to survive.

‘Perhaps they dodged out of the way,’ he suggested. ‘Or maybe they wore
hard hats.’

So don’t be a dinosaur, wear a hard hat this June.

Philip Bagnall is president of the Society of Meteoritophiles and a hard
hat-carrying member of the International Tunguska Expedition.

It turned out that Groucho’s brother worked for NASA (he said), though
he didn’t know in which lab. The rock weighed about a kilogram and he was
willing to part with it for $1000. No, I could not examine it before I
bought it, and speaking to his brother was out of the question (Harpo, no
doubt). I told him I would think about it and asked for his telephone number.
He didn’t fall for that one. He would ring me back. Needless to say, he
never did.

This particular piece of moon rock probably does not exist; the call
was simply someone trying to make a fast buck. The real giveaway was the
price. If a black market did exist in lunar material – and, as far as I
know, it does not – then I would expect to pay, perhaps, $1000 a gram.

Fortunately, NASA’s curatorial procedures account for every fragment
of moon rock and it is inconceivable that a kilogram chunk should go astray.
But although lunar materials are fairly secure, other cosmic specimens –
namely meteorites – are sometimes traded under the counter, so to speak.
And the main reason for this is the legislation introduced to protect these
specimens.

If a meteorite lands in your back garden then the thing is yours, in
Britain at least, providing you own the land on which it fell. You can sell
it, raffle it, donate it to the Natural History Museum or keep it as an
unusual paperweight. In other countries, however, the rules are different.

Take Denmark. Meteorites which fall on Danish territory – with the exception
of Greenland – automatically belong to the state. Hand over a newly found
specimen and you will receive a reward based on the weight of the meteorite,
its condition and rarity, and how well you looked after it. (Tip: if you
really want to impress the authorities, photograph the meteorite where
it was found, preferably next to a ruler, before wrapping it in aluminium
foil or placing it in a Teflon bag. They can’t ask for more than that!)
In Canada, you’ll receive a Finder’s Certificate for your troubles.

In Western Australia, they study meteorites which have fallen on the
Nullarbor Plain to help to determine the influx of such specimens over many
centuries. In order to ensure that the results are not invalidated by the
undocumented removal of meteorites, the state of Western Australia has
passed a law making it illegal to disturb them. But this has not stopped
one or two ‘professional’ meteorite collectors, who are now asking high
prices for Nullarbor specimens.

Argentina also has a protection order on meteorites – as American meteorite
trader Robert Haag discovered when the customs intervened because they suspected
he was about to remove some specimens which were particularly rich in iron
from the country. Haag is the Indiana Jones of the meteorite world and was
not at all perturbed by his close encounter with the Argentinian authorities.
Far from it – he is reported as saying it is the best publicity he has ever
had.

These kinds of protection orders have been imposed at the insistence
of professional meteoriticists who fear that a rare or unique specimen may
fall (no pun intended) into the hands of an amateur, thus depriving science
of a vital piece of the cosmic jigsaw. Their fears are not totally unfounded:
at least one rare moon rock is known to be in the hands of an amateur, and
there are rumours of another specimen which appears to be unique and which
should be fully investigated (‘Australia to crack down on fossil smugglers’,
This Week, 16 May).

It would be wrong, however, to give the impression that those who collect
meteorites for pleasure are at odds with their professional counterparts.
Many of the meteorites to be found in museums and in university collections
throughout the world are there because of the efforts of amateur meteoritophiles
who, in the past, have provided both specimens and funds for research. Most
collectors firmly believe that all newly discovered meteorites should be
made available for research.

The existence of protection orders has partly forced the trade underground,
as protection orders always do. Consequently, the price for protected material
is on the high side; anything from $20 to $2000 a gram for the rarer
meteorites. Offers are usually made over the phone or appear in mailed
lists which have restricted circulations.

Some meteorite traders feel that such precautions are unnecessary and
openly sell illegal specimens. They point out that by the time the authorities
get wind of what is happening the specimens will have been sold to collectors
in a dozen different countries and will be impossible to recover. As for
their own fate, the traders are confident in the knowledge that it is highly
unlikely that a country would begin extradition proceedings over something
as relatively unimportant as a few rocks from space.

Buying extraterrestrial materials is a bit of a dodgy business at the
best of times. While certain meteorites display structures that are totally
unknown in terrestrial rocks, others look remarkably like the stones you
find in your back garden – which is why so many meteorites go undetected.
Unless you happen to have a fairly well-equipped lab – and most collectors
do not – you could be buying almost anything.

Even fieldwise meteoriticists can sometimes be fooled. A rock collected
in the Lewis Cliff region of Antarctica in 1988, and thought to be a meteorite,
has since turned out to be Earthly in origin – but it took extensive tests
to prove it.

It is not only the meteorites themselves that are difficult to authenticate.
Tektites are dark, glassy objects which are the by-products of massive,
hypervelocity meteorites impacting with Earth. Unfortunately, they look
remarkably like obsidian, a terrestrial rock of volcanic origins. Not a
few of the ‘tektites’ in collections throughout the world are probably volcanic.

As for moon rock, there is one sure fire method of authenticating it.
Simply break the rock in two and if it does not have ‘Mare Tranquilitatis’
written all the way through it. . . Accept no fakes.

Philip Bagnall is president of the Society of Meteoritophiles and is
not in the market for moon rock, edible or otherwise. Alison Brooks is a
science writer and palaeontologist.