Belgian meteorite hunters scooting about Antarctica on skidoos have described what they say is the largest meteorite find on the frozen continent since 1988.
Geologist Vinciane Debaille of the Université Libre de Bruxelles told the International Polar Foundation that she and her colleagues on an international meteorite-hunting team searched the Nansen Ice Field at an altitude of 2,900m, 140km south of Princess Elisabeth Antarctica.
As is customary for polar meteorite hunts, the ten-strong team boarded skidoos and adopted “a V-shape, with the field guide in front of the V. We let 20 to 50 m between each participant, depending of the visibility and the potential dangers on the field, such as crevasse zones. Once someone finds a meteorite, he/she warns the others by radio, and the closest one comes to help by taking GPS position or pictures of the meteorites. Then, everybody retakes his/her place in the V-shape.”
On 28 January this method yielded 425 meteorites totalling 75kgs, with the prize being the 18kg whopper that Debaille put into perspective with this quote on what a meteorite-hunter expects to find:
“Per year, around 1,000 meteorites weighing less than 100g are found, and about 100 less than 1kg. So 1Kg is already special, never mind 18KG.”
The rock is a type known as a “chondrite”, the most common type of meteorite and of interest to science because they are not part of a larger body.
The specimen's large size presents several problems, one of which was that its finders didn't have a receptacle in which to place it. Touching with human hands is a no-no, lest it be contaminated.
“There are people studying the biological markers and organic, and we don’t add some more from us humans. So we try not to touch them,” Debaille said. “It’s easy when they’re small, you have a zip bag and you scoop them up. But when you have this large specimen and you think ok, I have to put it in a bag without touching it, and it was quite a challenge. Luckily our Japanese colleagues were well equipped, with a big bag that was large enough!”
Debaille also says “The meteorite is currently undergoing a special thawing process in Japan – to ensure water doesn’t get inside the rock.”
Debaille says another of the expedition's finds comes from the Asteroid Vesta, a deduction she is confident of because “We can measure what’s going on space, the spectral signature of the asteroid Vesta is the same as meteorites we find at earth, using measurements of reflected light. What is reflected is depended on the element on the asteroid, so we know the chemical composition of the Asteroid. When we have the meteorite we can see that it has the same chemical signature, so we know there’s a good chance it came from the same asteroid.”
Another find has a good chance of being a fragment of Mars.
The 18kg rock is destined to become a museum exhibit, once scientists have finished with it. ®