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180 kg CO3 meteorite
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Hello! |
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| - I am a small part of a larger rock and I come from space. - I don't remember when that event took place... Suddenly a dazzling light with a big sound, we have collided with something. I have been pulled out, and fell on an arid soil. - Since that time, I lay solitary... What's happened of my fellow travelers? |
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Many years later, 22 October 1999 |
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" I have found another one, it seems similar to DaG 847. Five samples on this area and this one is not a broken fragment, it's a very nice small individual." This type of pale, stoneless ground is every prospector's dream - provided he's the first on the scene. |
| The first sample of CO3 has been discovered in 1995, since that date, 35 samples have been recovered, which represents a total mass of 28 kg. |
| We have access to information about the positions of all carbonaceous meteorites found and analysed since 1995. This data shows a vague distribution ellipse, with the majority of small pieces in the south-eastern part of the oval, and specimens weighing one kilo or more in the north-western part. |  |
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North-west of the distribution ellipse, |
The plateau ends just in front of us, the small cliff which marks its edge overlooking a lightly undulating landscape with an old oued bed and alluvial deposits. |
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" The ellipse of fall stops straight the edge, hum... hard to believe!" |
| We have decided to go down the plateau in the north-west direction. If it's easy to drive in the central part of Dar al Gani, on hard chalky soil and flat area, descending rocky slopes and driving over soft ground is something rather tricky. Nobody crosses here as the nearest oasis and watering place is 100 km (60 mi) away as the crow flies, it also means the nearest watering place. A breakdown and you must walk three days, therefore it's recommended to go with two 4WDs.
Ready! |
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First trap is called "fech-fech", a very fine powder caused by erosion of the clay-limestone terrain, a pulverulent soil under a thin crust, not really discernible. Don't stop... |
Except when you see that kind of rock. |
| " Let me have a look on this small plateau. Quite rocky ! " We often think and feel sorry for our poor tires. When we manage to clamber up to little plateaus, they turn out to be covered with limestone slabs. Calcareous stones are shattering under the wheels producing dry noises and showing sharp edges which shred pieces of rubber. Few tires endure such torments day after day without a puncture. |
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One day prospecting, from left to right: - individual 3925gr - individual 3810gr - 4150gr in many pieces - three pieces joined together, the 3 stages of a 2655gr rocket: Dar al Gani 853
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| Now we are in a position to draw the distribution ellipse of the fall, which starts on Dar al Gani and continues in the north-west direction above sandy valleys and small rocky plateaus.
All the teams who prospect here on Dar al Gani, record as much information as possible in situ on each sample collected. This information (GPS locations, weight, photos... and of course complete classification) contribute to the data base for a better understanding of the Saharan meteorite population. Antarctica meteorites move from the point of fall, so the last remaining hot desert strewn fields have high scientific value and offer an unique opportunity of study meteorites "in situ". More than 30000 years of dry climate have been necessary to create such data base. |
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At that time of the expedition, 15 new samples have been recovered |
| At the north-west extremity of the ellipse, we notice a great concentration on a very small area (27kg on 2 square km). Another interesting point is the length, more than 24 km, while the width does not exceed 3 km. We can have a very good estimation of the trajectory. |
| A small meteorite loses rapidly all cosmic velocity and its final plunge to Earth is due to gravity alone, that means it falls on the trajectory of its "big brother".
Today's specimens lead us to believe that the meteor had an oriented, inclined trajectory 309° north. The pieces discovered in this area all weigh more than 2500 g. Some of them broke up on impact, but all originated from a first fracturing in the atmosphere. The most interesting of all is an elongated individual shaped like a rocket which broke into three on impact. The initial block must have been very large to produce a fragment shaped like this. Where is it? |
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23 October 1999 |
| Sun is rising, it's time to get up, have breakfast, plan the morning, enter way points in GPS and make a checkup on the 4WD. Trajectory of the CO3 fall seems to be 309°, we break down camp and head to the north-west for reconnaissance. |
| Just thirty minutes and 2 km farther. " No doubt we are following the proper direction." |
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CO3 complete individual 8300gr in situ |
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