uc Labenne does something very special. For the past 30 years he has been systematically combing expanses of desert in search of pieces of the Moon, Mars or meteors that struck the Earth one day. He then collects, lists and sells his finds. His latest thrill came when a fragment of an asteroid, now meteorite 2023 CX1, fell over Normandy on the night of February 13th 2023.

This specialist in interstellar rocks left a career in medicine to pursue his other passion and become a full-time meteorite hunter. He is now an internationally acknowledged expert and the main supplier to museums, science universities, as well as watch and jewellery brands in search of exceptional specimens. We met him.

Europa Star: How did your passion for meteorites come about?

Luc Labenne: As a boy, I was already picking up stones and observing nature. I’d go up and down the paths around where my grandmother lived, hunting for fossils. Sometimes I’d find fossilised sea urchins and shells, which for me was like finding treasure. When I was older, my father, my brother and I would go on desert treks looking for prehistoric tools. I remember coming across an article about two German geologists who’d been studying rocks in Algeria, looking for oil, and had found meteorites.

A meteorite strike is a rare occurrence. At that time the only systematic searches were in Antarctica. Meteorites which had become entombed in blue ice gradually appeared at the surface as the winds scoured away the ice above them. Scientists were able to observe that in certain zones there were concentrations of meteorites that had fallen to Earth over the course of hundreds of thousands, possibly millions of years, and expeditions were set up to search for them.

Luc Labenne with the Ghadames meteorite, a 24kg oriented piece with impact marks. (Photo Buonomo & Cometti)

How did meteorites end up in the desert?

The same way. It became apparent that there was an accumulation of meteorites in the desert, a landscape that hasn’t changed in hundreds of thousands of years. When I say “accumulation”, we need to put that into perspective. You might find one meteorite per square kilometre, which is a vast space to cover on foot or even in a vehicle.

The fact that I already had experience of the desert gave me the idea to go hunting for meteorites. They weren’t easy to identify back then. The internet was still in its infancy and the photos I’d seen in books showed slices of meteorite, which is a great way to see their inner structure but doesn’t tell you what you should be looking for out in the open.

I went on several expeditions before I finally found one. A meteorite is just a rock among other rocks. You need a trained eye to tell the difference. If it looks out of place, it’s probably a meteorite. I learned through practice. First I found one, then ten, then hundreds.

What’s so fascinating about the desert?

The silence. In everyday life we’re inundated with sounds, noise, voices. Provided there is no wind, the desert is the only place where there is no noise. That, and the landscapes… Anything can happen when you’re hunting for meteorites in the desert. Some people compare it to a treasure hunt. Maybe I’ll have found nothing by the end of the day, or maybe I’ll discover a meteorite whose composition will advance scientific understanding, or one that’s remarkable for its aesthetic.

What does it feel like to find a meteorite?

First, before I even touch a meteorite or pick it up, I document the find. This involves logging the GPS coordinates, taking photos, and other things. When finally I do have it in my hands, I think about how it travelled through space and that I’m the first human being to touch it. It’s fascinating. I try to imagine the trajectory of a rock which, in most cases, is 4.5 billion years old and could have come from the furthest reaches of the solar system, or from Mars or the Moon. A meteorite fall is always spectacular. There’s a boom like a thunderclap and a whistling sound as it passes through our atmosphere. There are also intense light phenomena. The emotion I feel each time I find a meteorite never goes away.

The Pallasite Seymchan meteorite: a very large slice with the “Widmanstätten pattern” revealed. (Photo Buonomo & Cometti)

Do you get information about where meteorites fall or do you search random locations?

You cannot predict a fall. It’s thought that in a given year, across the entire planet, between five and ten meteorites are seen to fall and picked up. That’s not many. Most fall into the ocean or in wilderness areas. The probability of tracking them is pretty slim. Sometimes we hear from people who saw a meteorite fall in such and such a place, in such and such a country, and everyone rushes to the scene and starts searching the vicinity. I prefer to carry out systematic searches in parts of the desert. You have to pay attention and hope that you might, possibly, discover an extraordinary meteorite. Although in a way they’re all extraordinary.

You have to give a fragment of every meteorite you find to the scientific community. Why?

For a meteorite to “exist” and be recognised by the scientific community – and a meteorite is first and foremost a scientific object – you must give a 20% fragment for rocks up to 100 grams and 20 grams above that weight. This sample will be analysed and used to establish its classification. The meteorite will then be given a name and this, along with other information identifying it, will be published in the Meteoritical Bulletin of the Meteoritical Society. Currently, around a thousand scientists are working on meteorites worldwide. When they publish their research, they must indicate the name of the meteorite in question, hence it has to have an officially recorded identity. The sample is then conserved at a scientific institution or museum as a reference sample.

The Martian meteorite NWA 7533, the star of Luc Labenne’s collection. Thanks to this meteorite, scientists were able to confirm that there was water on Mars with a neutral pH of 7, which can support life.

In November 2022 scientists at the University of Alberta identified two minerals in the El Ali meteorite – elaliite and elkinstantonite – that had never been seen before on Earth. Is this the kind of discovery you mean?

You often read about the discovery of unknown minerals when there are actually dozens of high-pressure minerals that are only known to occur in meteorites, because they have been exposed to pressure that doesn’t exist on Earth. It makes for a great story but there have always been new minerals and there always will be.

All meteorites are exceptional but are some more exceptional than others?

Roughly 98% of meteorites are fragments of asteroids from the asteroid belt between Mars and Jupiter. These blocks can measure anything from a few dozen metres up to 1,000 kilometres in diameter, virtually protoplanets. From time to time, because there are so many of them, the orbit of an asteroid changes and intersects with Earth’s orbit, which is how a meteorite appears. Its trip through the atmosphere before reaching Earth is violent. It enters the atmosphere at a speed of tens of kilometres per second, and will be subjected to very high temperatures and huge shocks. When a meteorite burns up, a black crust forms around it. It will also break into multiple pieces. These rocks provide scientists with valuable information because their composition hasn’t changed in around 4.5 billion years. They are the “building blocks” for all the planets. There should have been another planet in the asteroid belt, but Jupiter is so huge it prevented these blocks from coalescing and forming a planet.

Which are the rarest?

Lunar meteorites and Martian meteorites. A fragment of asteroid must crash into the Moon with sufficient force for a lump of moon rock to be propelled into space, and then it has to intersect Earth’s orbit. It’s an extremely rare occurrence. For many years, finding a lunar meteorite was a huge deal! Over the past twenty years, however, thanks to systematic searching, several dozen have been listed. A lunar meteorite is much rarer than diamond or gold.

Martian meteorites are formed the same way. So far, more or less the same number of Martian meteorites and lunar meteorites have been identified. They are of huge scientific interest because they enable scientists to understand the history and composition of the Moon and Mars, which has become a focus of attention in recent years. Mars has a similar history to Earth, but something happened to make it lose its atmosphere and water. Martian meteorites are the only access we have to rocks from Mars. The Apollo missions brought back samples of moon rock but nothing has been brought back from Mars. Each planet’s history is contained in that rock.

How do you recognise them?

I use a spectrometer to analyse a rock’s composition. This tells me if it’s a lunar or a Martian meteorite. They have very different compositions. It’s impossible to mistake them; their chemistry is totally different. The detailed analyses required for official publication are carried out by scientists.

Louis Moinet’s Super Moon timepiece features an authentic lunar meteorite fragment, protected by an anodised aluminium capsule. This is an extremely rare and precious material, as fewer than 400 lunar meteorites are known to exist worldwide.

What about value? How is that defined?

When I first became interested in meteorites, in 1994-95, very few had been found and there were no set criteria on which to base value. Over the past ten years or so, demand has grown significantly. The number of collectors has increased. Meteorites are used for watches and jewellery. Scientists want them, too. As a result, we can now establish prices for them.

Scientific interest is the major criterion when defining a meteorite’s value. Rarity is another. There are around forty types of meteorite, lunar and Martian being the rarest and most sought-after. Aesthetics can be another factor. A meteorite that proves to be particularly attractive when cut and polished will be most in demand for watches and jewellery. Collectors tend to look for the more beautiful specimens, too. Outer appearance is also something to take into account. As they pass through the atmosphere, certain meteorites take on a specific shape. We call these “oriented meteorites”. They look a little bit like a shield and molten metal forms flow lines on the surface. These are the ones collectors most want.

Provenance can also influence value, as can history. Meteorites that fell in the eighteenth and nineteenth centuries, for the oldest, and which still have their museum label are highly sought-after, even if they don’t necessarily present any great scientific interest.

You mentioned aesthetics. Are there certain criteria or is beauty in the eye of the beholder?

As soon as you become interested in meteorites, you’re drawn to the oriented specimens I just described. Internal appearance is really a matter of individual taste although there are certain textures that appeal to everyone, such as when there is a small amount of metal in a dark matrix. One meteorite in particular stands out and that is pallasite, which contains olivine, or peridot, crystals set into a metal matrix. These crystals act like windows, allowing light to pass through. Pallasite is extremely rare, very beautiful and highly coveted. The only problem is that certain pallasites can become altered and rust. Needless to say, I only deal in quality pallasites that do not rust and do not oxidise.

This version of the Hermès Arceau L’Heure de la Lune cleverly combines a lunar meteorite dial with the simultaneous display of the phases of the moon in the northern and southern hemispheres.

What do you find most fascinating about a meteorite?

Whenever I find a meteorite, I think maybe this is the one that will help fill the gaps in our knowledge of how the solar system formed. A meteorite is a visitor from space and a discovery is always an emotional experience. It’s something I like to share with customers. Every meteorite has a story to tell.

Which is the star of your collection?

A Martian meteorite, NWA 7533, that has a unique composition. It was discovered ten years ago, has been the subject of numerous scientific publications and is still being studied today. Thanks to this meteorite, scientists were able to confirm that there was water on Mars with a neutral pH of 7, which can support life. They were also able to date the zircons it contains as being 4.4 billion years old; the oldest known. They show that around 100 million years after it began its formation, Mars had a solid continental crust, like Earth. In terms of understanding how Mars formed and the potential possibility that life developed there, this is a major discovery.

You’re talking about the famous “Black Beauty”?

Yes, that’s the one. Someone gave it the nickname “Black Beauty” but its proper scientific designation is NWA 7533. NWA because it was found in northwest Africa.

Any recent experiences?

I’d just got back from Chile when I heard that an asteroid would enter the atmosphere during the night of February 13th. Astronomers had calculated its path and predicted that it would fall somewhere in Normandy. As of that Sunday, dozens of professionals and amateurs were pointing their cameras skywards, hence there are numerous photos and videos of this fireball entering the atmosphere. It was even seen from England. On February 15th I decided to drive up to Normandy and see for myself. My son didn’t have school that day, so he came with me. Once there, I was able to use my spectrometer to confirm that one of the rocks found was a meteorite. It’s incredible that we were able to actually see the asteroid before it struck Earth!

And the one you would love to find?

My grail would be a Martian meteorite containing an element that would prove that, at some point, there was life on Mars. The ultimate dream would be to find a meteorite with a fossil from Mars. Maybe there is just such a rock on Mars, who knows?