Earthquakes are just one of the ways the Universe is trying to kill us, and it’s a relatively tame method compared to the Universe sending rocks at the surface of the planet. Just one big rock, and bye-bye, dinosaurs!

Then you take a look at the surface of the Moon and think, that’s a lot of craters! Good thing Earth doesn’t look like that. Except that it kind of does, and we hide it really well with vegetation and erosion. Still, it’s a bit shocking to find two large craters close to one another here on Earth, and for a long time, scientists thought that these double craters were the result of binary asteroids — two asteroids orbiting each other that hit the Earth at about the same time.

That hypothesis was disproved because binary asteroids orbit each other too closely to leave separate craters. They would have to enter our atmosphere separately, and that’s not a likely scenario.

Now, in recent research published in the journal Scientific Reports, a team led by Elmar Buchner has analyzed two craters in Germany to understand their provenance. One of the two is the 24-kilometer Ries crater that encompasses the town of Nördlingen, and the other is the 4-kilometer Steinheim Basin, about 40 kilometers away. The team found that the Ries crater is about 11.8 million years old, and the Basin is thought to be about the same. Plus, the rocks in the area show evidence of two separate seismic events, which means that the region got a one-two punch of asteroid strikes, maybe a couple hundred thousand years apart.

Planetary scientist William Bottke, who has studied double craters but wasn’t involved in this particular research, noted: If you only have so much terrain and you keep adding craters, eventually, two are going to be very close to one another, just by chance.

Sorry, Germany.

More Information

Eos article

“New discovery of two seismite horizons challenges the Ries–Steinheim double-impact theory,” Elmar Buchner, Volker J. Sach and Martin Schmieder, 2020 December 17, Scientific Reports