Gothenburg, Sweden – Researchers recently found evidence of a double meteor impact that occurred in the Swedish County of Jämtland, around 460 million years ago. According to Erik Sturkell and colleges from the University of Gothenburg in Sweden, the meteors that formed the craters landed just a few miles from each other at the same moment.

“The two meteorite impacts occurred at the same time, 458 million years ago, and formed these two craters,” explained Sturkell, Professor of Geophysics at the University of Gothenburg.

The team found one of the craters 20 km south of Östersund in Brunsflo and its enormous diameter was of 7.5 km. The smaller one is located 16 km from the first location, and has a diameter of 700 m.

Trail of the asteroid that exploded over Chelyabinsk, Russia, on Feb. 15, 2013.
Credit: Alex Alishevskikh CC BY-SA 2.0.

The historical province of Jämtland was under the sea at the time, 500 m below sea level when the two meteorites impacted the Earth. This double phenomenon are very unusual. This is actually the first double impact on Earth that has been conclusively proved. After the collision, the water was forced away and for a hundred seconds the enormous pits were completely dry.

“Around 470 million years ago, two large asteroids collided in the asteroid belt between Mars and Jupiter, and many fragments were thrown off in new orbits. Many of these crashed on Earth, such as these two in Jämtland,” said Professor Sturkell.

According to the authors of the research, these were far from being the only meteor impacts by the time. “The water then rushed back in, bringing with it fragments from the meteorites mixed with material that had been ejected during the explosion and with the gigantic wave that tore away parts of the sea bed,” said Erik Sturkell.

Other impacts on Sweden

Other meteorites have also been found on Kinnekulle, located at the province of Västergötland. Over the past 15 years, around 90 meteorites impacts have been found on the site.

“In the 1940s, an unusual-looking red limestone slab was found in a quarry. A few years later, researchers understood that there was a meteorite in the slab. Large meteors explode and disintegrate almost completely, while small meteors fall as rocks, such as in this limestone,” explained Erik Sturkell.

Source: University of Gothenburg