_
_
_
_

How to find a meteorite in Antarctica

Glaciologist Veronica Tollenaar published a ‘treasure map’ revealing the possible location of more than 300,000 space rocks

Meteoritos Antartida
Glaciologist Veronica Tollenaar, taking samples on an area of blue ice on the Ellsworth Mountains.claudio álvarez

Humanity discovered the existence of Uranus, in 1781, before finding out about the presence of a sixth continent on its own planet, which did not happen until 1820. That belated discovery of Antarctica and its gargantuan ice cliffs triggered the imagination of writers: Edgar Allan Poe envisioned a route full of bloodthirsty, savage tribes; Jules Verne fantasized about a magnetic sphinx at the South Pole; and H. P. Lovecraft placed the Mountains of Madness, populated by voracious, fetid creatures, there.

Dutch glaciologist Veronica Tollenaar tells an equally amazing (and true) story as she casually walks through deep Antarctica. Under the blanket of snow, says the researcher, there are no monsters or relics from forgotten civilizations; there are space rocks from other worlds, however, perhaps with signs of alien life. The most anticipated piece of news of all time, that we are not alone in the universe, could be concealed somewhere under her boots.

It all started with a joke. A few months after astronaut Neil Armstrong first set foot on the Moon in July 1969, in the midst of the global space exploration fever, Japanese geologist Masao Gorai jokingly told some colleagues that were going to Antarctica to bring him some meteorites. A few days later, the expedition came upon a strange black rock in the ice. Then, another. And another. In just 10 days, nine meteorites had been found.

That enigmatic finding revealed an unsuspected mechanism. The snow that falls in Antarctica compacts and after some centuries becomes immaculate ice with no bubbles, which sinks and moves a few meters each month in monumental glaciers. Tollenaar estimates that several hundred meteorites weighing more than 50 grams (two ounces) fall on the continent each year, eventually disappearing from sight in the depths of the white mantle. However – she says enthusiastically – there are points in Antarctica where these rivers of ancient ice end up running into a mountain and emerging. The buried meteorites surface in areas of blue ice. Harry Zekollari, her colleague, found more than 400 space rocks in a single expedition. “We made a treasure map to find these places full of meteorites,” Tollenaar declares.

The English explorer Frank Bickerton was the first person to collect a meteorite in Antarctica, in 1912. Since then, almost 50,000 space rocks have been found on the white continent, 62% of all that have been found on Earth. It is not that more fall here; they simply accumulate over millennia in specific areas, in full view of anyone who happens to pass by. “Almost all meteorites come from the asteroid belt, but there are also some from Mars and the Moon,” says Tollenaar, from the Free University of Brussels (Belgium). Her team used machine-learning computer tools to calculate, with an estimated accuracy of 80%, where the meteorites may be appearing: particularly cold areas of blue ice on moderate slopes. The result of their work is a public map that poetically asks, “Where to catch a falling star?”

One of the most famous meteorites in history is the ALH 84001, a Martian rock that was ejected from the red planet 16 million years ago and fell in Antarctica about 13,000 years ago. In 1996, a NASA team ruled that it contained chemical compounds that were likely produced by extraterrestrial microbes. President Bill Clinton himself solemnly presented the finding to the world: “[The meteorite] speaks of the possibility of life. If this discovery is confirmed, it will surely be one of the most stunning insights into our universe that science has ever uncovered,” he proclaimed at the time (a year ago, other American scientists proved that those compounds could have formed without the intervention of Martian microbes).

A dreamlike setting

It is a fine day to be in deep Antarctica: it is 5 degrees Celsius below zero (23 Fahrenheit). The glaciologist walks under the sun through a dreamlike setting that scientists call “the beach” due to its resemblance to a small frozen sea, about 1,000 kilometers (621 miles) from the South Pole. “Meteorites always appear in blue ice like this,” explains Tollenaar. The Ellsworth Mountains, the highest mountain range in Antarctica, loom around her. One peak, known as Elephant’s Head, looks as if an extinct civilization carved a giant pachyderm before fading into oblivion – a scene that could easily fit into the wildest fantasies of Allan Poe, Verne or even Lovecraft.

“Antarctica is the best place to find meteorites. They are concentrated in specific areas and they can be spotted easily, being a black thing on the blue ice. A meteorite that falls in an agricultural region or a forest is almost impossible to find. In addition, it’s very cold here, so they are better preserved; they don’t deteriorate,” explains Tollenaar. “There are areas where every rock you find is a meteorite.”

Military explorer Juan Pablo Muñoz makes a hole in the ice with an ice ax.
Military explorer Juan Pablo Muñoz makes a hole in the ice with an ice ax.Claudio Alvarez

The researcher’s analysis, published a year ago in the journal Science Advances, suggests that less than 13% of the meteorites on the continent’s surface have been found, with the more than 340,000 remaining space rocks concentrated where her maps shows. The Dutch glaciologist is taking part in an 18-day expedition to the Chilean Glacier Union Scientific Station, organized by the Chilean Antarctic Institute, in which she and her colleague José Jorquera study the properties of snow and ice to try to understand how global warming is affecting the surface of Antarctica. Tollenaar is also seeking funding to organize future missions to the meteorite sites on her treasure map.

Geologist Ralph Harvey is the head of the Antarctic Search for Meteorites program, an American project that in half a century has found approximately 22,000 specimens. The veteran meteorite hunter applauds the new treasure map made by Tollenaar’s team, which will serve to prioritize search locations, he says. However, Harvey points out that Antarctica is a nightmare where temperatures of minus 89 degrees Celsius (128 Fahrenheit below zero) and hurricane winds of more than 300 kilometers per hour (186 mph) have been recorded. “The task of recovering Antarctic meteorites is only 10% science; the rest is training, planning and logistics,” warns the researcher from the Case Western Reserve University, in Cleveland, Ohio.

Ancient ice, in the vicinity of the Chilean camp of Glacier Unión.
Ancient ice, in the vicinity of the Chilean camp of Glacier Unión.Claudio Alvarez

Looking for meteorites at the end of the world

The idea of making a treasure map came from Belgian glaciologist Harry Zekollari. A decade ago, this researcher participated in an expedition to look for space rocks in the area around the Belgian Princess Elisabeth station. In just over five weeks they found 424 meteorites, weighing a total of approximately 70 kilos (154 pounds). “The areas of blue ice make up 1% of the surface of Antarctica, but in most of them you won’t find any meteorites. The big question here was why there were some in a certain area, but none in another site that was only 10 kilometers (six miles) away,” he recalls. That is where Veronica Tollenaar came in.

She had never imagined that she would end up looking for meteorites at the end of the world. For years she saw herself earning a living through music, her great passion, as a flutist with a repertoire from medieval, renaissance, baroque and contemporary times. Meanwhile, she studied civil engineering and learned how to use artificial intelligence tools that are not common among her fellow glaciologists. This unusual training allowed her to make the first treasure map of Antarctic meteorites, as part of her doctoral thesis.

An area of blue ice in the surroundings of the Chilean Glacier Unión camp.
An area of blue ice in the surroundings of the Chilean Glacier Unión camp.Claudio Alvarez

Tollenaar kneels on the blue ice and takes samples with her hammer. In deep Antarctica, everyone has a nom de guerre, which is used in radio transmissions. The glaciologist is Thor, like the hammer-wielding Norse god of thunder. Two military scouts from the Chilean Army nicknamed Face and Prometheus go a few meters ahead, opening holes with their ice axes. Tollenaar explains that not all space rocks are worth the same. “Maybe only one in 100 meteorites is special. So, in order to get that special meteorite, you need to find the other 100 as well,” she explains as she continues to hit the blue ice with her hammer.

More information

Recomendaciones EL PAÍS
Recomendaciones EL PAÍS
_
_