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Journal

No. 50 - November 2006

Let there be rock - The story of the Hambleton meteorite

a rock in the hand ...
A rock in the hand is worth 10 in the field. Photo Rob Elliott.

The discovery of a new meteorite in the U.K. is big news. But when the new find is a Pallasite, then you need to re-calibrate your Big News Detector! To find a meteorite, even an ordinary chondrite is very rare, but to find one of the rarest types of meteorites (only 1 % of all falls are pallasites) then this is cause for excitement. The meteorite in question is the first of its kind to be discovered in the British Isles.

Rob Elliott of Fernlea Meteorites lives in Fife, Scotland. He has found several small meteorites, notably the small several gram stone Glenrothes while out fishing. However, he has always kept his eyes to the ground when rambling the countryside. This was to prove extremely fortunate last year when out with his wife Irene on the Yorkshire moors on a meteorite hunt. This area of moorland is an undeveloped piece of countryside and ideal for meteorite hunting as the land has remained unturned for a long period of time. A large rock weighing 17.6 kg was found and the magnet Rob always carries was attracted to this curious rock. It was thought to be a possible suspect in the search for extra terrestrial interlopers. It was duly hauled out of the muddy undergrowth and taken home where it ... sat outside for three months in the glorious Scottish wind, rain and sleet! Now, you and I as meteorite enthusiasts would probably balk at this location, but hear me out. It was thought to possibly be a meteorite due to the magnetism, but in reality it was more likely to be some iron slag. After all it had a thick and extremely friable rust covering and a strange sulphurous smell. So it wasn't going to be house guest just yet.

The nearest town to where this rock was found is the small village of Kilburn in North Yorkshire near the Hambleton Hills. The outline of the White Horse of Kilburn is a well-known landmark on the hillside. Narrow country lanes criss-cross the pasture land, many of which are shown as farm tracks. Strangely enough, they are shown up on satellite navigation systems as passable to all traffic and yet only safely negotiable by four-wheel drive vehicles. It was along such a track that the Elliotts drove, parked the Land Rover and went hunting for meteorites. This was in summertime with a lot of greenery. This can be an obstacle, as meteorites can be obscured by undergrowth for a large part of the year. Yet luck was on their side as the rock was found by a wall and relatively easy to retrieve.

After a couple of months Rob hacked off a sample which was sent to Dr. Monica Grady, now at The Open University. She is at the time of writing involved in the analysis of the Stardust samples supplied by NASA from the sample return mission to Comet Wild 2. Dr. Diane Johnson of the Planetary and Space Sciences Research Institute was asked by Monica to communicate directly with Rob as she was doing the SEM mineral analysis. It turns out that the meteorite is a main group pallasite with a really beautiful small scale Widmanstatten structure that is clearly visible in the SEM scan emailed to Rob.

The first I heard of this meteorite was from Rob in August or September 2005 when he mentioned by email that he might have found something of interest. The next I heard was when my wife Pamela was given a newspaper cutting from The Daily Record from January 14th 2006. I emailed Rob straight away and I was invited over to see him, Irene and the new find in January 2006. After the short drive from my home town of Edinburgh to the Elliott's I was ushered into their living room. We had a cup of tea and then the baby was brought out for me to coo and gurgle over.

I was instantly mesmerised. If Rob had brought in John Lennon's Rickenbacker and an autographed copy of Revolver I couldn't have been more in awe! I have seen many a polished slice of a pallasite but this was how it had lain untouched for decades even centuries. I was quite surprised at the weight of this rock, which was the only hint other than the small off cut, that this could be a rock of great value. It was found near the village of Kilburn in Yorkshire and was probably lifted from its original fall site by a farmer then ditched over a wall. This is pure speculation, and it is a wild guess that the grooved furrow on one side could have been caused by a plough.

The picture below shows Hambleton almost as it was found (bar the small piece cut off for analysis). Note the furrow along the top.

Hambleton, groove on top
Hambleton showing groove on top and cut end. Photo Angus Self.

Diane Johnson emailed Rob with some interesting details about the meteorite. Apparently it is from the main group of pallasites as found by the oxygen isotope data in the olivine. Two small blocks had been cut from the sample and were polished. They both show Fe-Ni metal and olivine. One other issue of interest is the discovery of iron sulphide and phosphorous. Although Diane suspects the phosphorous may be due to the weathering of the metal. Perhaps this was the cause of the unpleasant smell! As I write, the Meteoritical Society is still to publish this find in its bulletin but there is hope that by March 2006 it will be posted.

scanning electron microscope image
Scanning electron microscope image. Note scale on right. Image Open University.

Whilst chatting with Rob I found out there were one or two strange rumours about this meteorite. Somebody has been reporting that Rob witnessed it as it fell from the sky. Strange, as the weathering leads to believe it has lain unfound for 200 years or so. Exact terrestrial age is uncertain, but this is an approximation due to the thick rust coating.

There is also the possibility that it could be the result of a fireball seen in 1783 travelling from Scotland to London centred over the Yorkshire area of the Hambleton hills. I was given the following information by Eric Hutton who has an astronomy web site with a list of historic meteor sightings.

1783, France, England, Scotland Aug 18th
R. P. Greg in his catalogue 1860, gives the following entry...

A very celebrated and remarkable meteor. First seen in the Shetland Isles; like the planet Mars; 1/3 moon, from Mullingar to York; equal 2 full moons over Kent; appeared to burst into two straight over Lincolnshire, with a report 8' or 9' heard at Windsor afterwards; visible 20"; at once for an arc of 75 degrees; 60 miles high; 20 miles in a second; tail 10 > than body; turned a little to E. after partially bursting; left a streak and sparks; tail not much seen at first, perhaps foreshortened. In Ireland, seen moving parallel to horizon 10 degrees or 12 degrees high. Seen over Burgundy in France; altogether for a distance of 1200 miles. At Greenwich as a double bolide, very brilliant. Heard to explode also over York some minutes after.

Rob has been on local television in the Yorkshire area showing his find and several other meteorite hunters have been interested enough to try their luck at finding more. However, after five more days of searching the area Rob has found no further pieces of this meteorite.

As a wise man once said "seek and ye shall find". Keep looking, this stuff is out there! Let there be rock!

Thanks to:

Angus Self, FBIMS,
February-March 2006,
< gus @ angusself.co.uk >

BIMS logo


Contents

Cover page

Presidential news

The March 29 eclipse from Libya

Let there be rock - The story of the Hambleton meteorite

Let there be rock - addendum

Brown dwarfs

About the ASE Journal


This journal as a single web page


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