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| The expedition team pose next to the massive new meteorite. The researchers are Maria Schönbächler (white helmet), Maria Valdes (green helmet), Ryoga Maeda (black helmet) and Vinciane Debaille (orange helmet). (Image credit: Alicia Valdes/Field Museum) |
On a recent expedition to Antarctica, researchers discovered five
perfectly-preserved meteorites that have likely been hiding beneath the ice
for thousands of years.
Scientists recently scooped up one of the heaviest meteorites ever
discovered in Antarctica, as well as four other frozen space rocks that
likely crashed into the icy continent thousands of years ago.
The researchers found the minihoard of meteorites on the surface of the Nils
Larsen blue ice zone near the Belgian-owned Princess Elisabeth Antarctica
station. Of the five meteorites, the standout was a cantaloupe-size rock
that weighed a whopping 16.7 pounds (7.6 kilograms). Of the 45,000
meteorites discovered in Antarctica, only around 100 have been as heavy as
this cosmic cannonball.
"Size doesn't necessarily matter when it comes to meteorites, and even tiny
micrometeorites can be incredibly scientifically valuable," expedition
scientist Maria Valdes, a meteoriticist at the Field Museum in Chicago, said
in a
press statement. "But of course, finding a big meteorite like this one is rare, and really
exciting."
The meteorites were found on the surface of the ice in early January, but they
did not crash to Earth recently. Instead, the space rocks were likely buried
in the ice for thousands of years and resurfaced only after the churning
motion of glaciers brought them back to the surface. But because the
meteorites were shielded from precipitation, wind and air beneath the ice,
they were still perfectly intact, according to the researchers.
"The objects come from the asteroid belt [located between the orbits of Mars
and Jupiter] and probably plopped down into the Antarctic blue ice several
tens of thousands of years ago," expedition scientist Ryoga Maeda, a
doctoral student at the Free University of Brussels,
told Belgian news
site The Brussels Times.
Normally, scientists have to scour the ice sheets in hopes of stumbling
across a meteorite. But the researchers were able to narrow down their
search thanks to a study published Jan. 26, 2022, in the journal
Science Advances, which used satellite data and a type of artificial intelligence called
machine learning to identify parts of Antarctica where meteorite clusters
were more likely to be brought to the surface. It was in one of those
hotspots that the newfound meteorites were discovered.
But even with a specific location to search, it still took a lot of hard
work to find the meteorites. "The reality on the ground is much more
difficult than the beauty of satellite images," lead expedition scientist
Vinciane Debaille, a geochemist at the Free University of Brussels, said in
the statement.
The team covered a large area, which was strewn with other non-meteorite rocks
of similar shapes and sizes. The researchers were constantly fooled by
"meteor-wrongs," which looked similar to space rocks but were much lighter and
originated on Earth,
CNN reported.
The meteorite samples collected during the expedition have been sent to the
Royal Belgian Institute of Natural Sciences in Brussels to be properly
thawed and analyzed, but each expedition scientist also took back samples of
potential meteorite dust, which they collected from around the fallen space
rocks, for their own research, according to the statement.
The expedition was the first to search one of the potential meteorite
hotspots highlighted by the 2022 satellite study. The team's success
suggests that the study could be used by other researchers to recover even
more frozen meteor fragments. In the study, researchers estimated that as
many as 300,000 meteorites could lie in wait on the surface of the ice,
meaning only around 15% have been recovered to date.
The expedition team hopes more meteorites can be found to help us learn more
about our cosmic neighborhood.
"Studying meteorites helps us better understand our place in the universe,"
Valdes said. "The bigger a sample size we have of meteorites, the better we
can understand our solar system, and the better we can understand
ourselves."