A decade ago, a mysterious crater appearedΒ in the Russian Arctic, forming a huge jagged hole hundreds of feet wide, plunging down into an inky abyss.
It was surrounded by enormous chunks of soil and ice, testament to the violent forces that created it.
Since 2014, more than 20 such craters have exploded, pockmarking the remote landscapeof northwestern Siberiaβs Yamal and Gydan Peninsulas β the most recent of which was discovered in August.
The craters have both intrigued and baffled scientists, who have spent years trying to unravel how they erupted into existence. A series of hypotheses have emerged, including wilder theories like a meteor strike or even aliens.
The team behind the new research decided to approach the questions like detective work, said Ana Morgado, a study author and chemical engineer at the University of Cambridge.
They first considered whether the explosions might be chemical reactions, but this was quickly ruled out. βThere was no reporting of anything related to chemical combustion,β Morgado said.