‘Star scar’ explored to unlock space secrets

ROCHECHOUART, France — Since early September, the denizens of this normally hushed burg in central France have been serenaded by an industrial drill poking holes around town and pulling up cylinders of rock.

That’s because Rochechouart, population 3,800, and its medieval castle are built on top of an astrobleme.

“An astrobleme — which literally means ‘star scar’ — is the name given to traces left by a major meteorite impact,” said Philippe Lambert, one of the astrogeologists trying to unlock its secrets.

This particular impact crater was made by a massive space rock that crash-landed more than 200 million years ago, and has intrigued scientists since its discovery in the 19th-century.

“You have a nugget under your feet!” famed Canadian astrophysicist Hubert Reeves said in 2011.

Since then, scores of scientists — geologists, paleontologists, exobiologists — have submitted requests to examine the space rock up close.

Lambert — who devoted his 1977 doctoral thesis to France’s only known astrobleme — today directs the International Center for Research on Impacts at Rochechouart.

The center is coordinating the first drilling and excavation at the site.

“About 200 million years ago — before the Jurassic period, and even before the planet’s continents split apart — a sixbillion-ton meteorite about a kilometer in diameter crashed here,” said Pierre Poupart, who overseas a natural reserve set up around the crater.

“It was traveling at about 72,000 km/h.”

The impact — which vaporized the meteorite — was roughly equivalent to several thousand Hiroshima-sized atomic bombs, and almost certainly destroyed all life within a radius of some 200 km. The landscape was changed forever.

The drilling, scheduled through November, will yield 20 core samples taken up to 120 meters below the surface from eight different sites across a 50-hectare area.

The $700,000 project could be the beginning of a long adventure, Lambert said.

“There’s everything here to justify an open-air laboratory,” he said.

Some scientists hope to tease out remaining mysteries about how such meteorites form, and what that might tell us about their evolution in space.

Others are on the hunt for chemical traces that could shed light on the emergence of life on Earth, and which of the raw ingredients essential for life came from space.