It’s a first: an astronomer discovers that a small asteroid is moving towards Earth. A little later the meteorite hits. Just two days later, the first fragment was found. However, a larger find would almost have been auctioned off piecemeal.
Inauguration ceremony for ten small meteorites in the Natural History Museum of Paris: Brigitte Zanda points to one of the stones in the brand new display case. It’s barely bigger than a ping pong ball. “Seven hours before the impact, an astronomer discovered the asteroid 200,000 kilometers from Earth,” says the astrophysicist. «Almost three days later, Lois found this stone in a field in Normandy. There’s never been anything like this before.”
Quick find in Normandy
Lois Leblanc had previously searched for meteorites. “In a meadow with tall grass, it was hopeless,” says the 18-year-old student. “But here we were walking across a winter field. At first we only found potatoes, but after just 20 minutes I came across an unusual stone.”
Citizen scientist finds fragment in the field
The 94-gram fragment in the display case has a black enamel crust and slight dents, like thumb prints. At the break point you can see that it is light gray inside, with shiny metal grains. The eight smaller fragments were found a little later.
Stones from space change on Earth.
“Meteorites contain metal, and it rusts when it comes into contact with moisture. Such a fresh stone is particularly valuable for us,” says Brigitte Zanda, who researches at the Institute for Mineralogy, Materials Physics and Cosmochemistry in Paris.
Asteroid, meteoroid, meteorite, meteor and shooting star
Between the sun and the eight planets of our solar system, millions of small astronomical bodies fly through space. Including asteroids. This is ancient Greek and means star-like. Because asteroids appear tiny in the telescope and are as numerous as stars. But there aren’t any, they’re probably just loose piles of rubble, held together by gravity. The rocky formations were left over from the formation of the solar system 4.6 billion years ago. They revolve elliptically around the sun.
Chunks keep breaking off from the asteroids. As long as such fragments float around in space, they are called meteoroids.
Our planet Earth is somewhat protected by the atmosphere. The mostly porous meteoroids burst upon entry and completely or partially burn up due to the speed and friction of the air. They appear as a bright glow in the sky. We speak of a meteor or – much more commonly – a shooting star. If the meteoroid does not burn up completely when it enters the Earth’s atmosphere and lands on Earth, it becomes a meteorite.
Scientists have already counted well over a million asteroids in our solar system. However, their total mass is smaller than our moon.
The stones from space are the only terrestrial access to the solar system and are therefore extremely important for research purposes. Their collectors are primarily drawn to the North African deserts and Antarctica, where a particularly large number of meteorites are found.
Thanks to the advance notice, hundreds of astronomers were able to film the asteroid entering the atmosphere as a fireball at 4 a.m. on February 13 and burning up on the Normandy coast. A little later, meteorite hunters arrived to comb the ten kilometer long and one kilometer wide recovery area not far from the port city of Dieppe. But interested citizens, so-called citizen scientists, like Lois Leblanc, also came to support science.
Professional finds a fragment in a hole in the ground
The largest find, weighing 175 grams, was almost lost forever, says Bil Bungay, an American meteorite enthusiast. He met his compatriot Steve Arnold in the impact area. «Steve is a professional, nobody has as much experience as him. He found the fragment in a hole 15 centimeters below the earth’s surface.
Largest find secretly sent to the USA
The commercial meteorite hunter boasted about his trophy on the Internet, then sent the stone unnoticed to the United States. There he tends to auction off his finds piece by piece. Bil Bungey stepped in and quickly bought the meteorite. Undamaged.”These fragments are now part of French history. People will continue to engage with the information they provide us for centuries to come. For me they are more valuable than diamonds.”
A look into the early days of the solar system
The stones from space are 4.6 billion years old. Thanks to the large amount of data and records, they provide particularly valuable insights into the early days of the solar system, when the Earth did not yet exist. Without a space mission.
Ludovic Ferrière is curator of the world’s largest and oldest meteorite collection at the Natural History Museum in Vienna. As soon as the first fragment was recovered in the Norman village of Saint-Pierre-le-Viger, the geologist jumped on a plane and took it to Bratislava via Vienna. The university there has a special laboratory for measuring cosmogenic radionuclides. When a meteorite enters the Earth’s atmosphere, the radioactive elements decay. “Never before have we been able to examine a meteorite as quickly as we did here,” says Ferrière.
The researcher also separated tiny samples for himself and other colleagues, one of which is being analyzed at ETH Zurich. Using an electron beam microprobe, he himself was able to determine that it was an “ordinary chondrite”. So called because it is one of the largest class of meteorites. For him personally, however, the stone in the showcase is a completely extraordinary object.
“We know more than 70,000 meteorites, but we can only trace the history of 35 to the parent body, i.e. to a group of asteroids with similar orbital elements. With the fragments from Normandy, we have more data and information than ever before, from its approach from 200,000 kilometers away to the measurements just days after it landed. This is unique.”