Holes like this one have been appearing in Siberia — at least three are known so far. There are a couple of theories for what's causing them and both are linked to climate change.

First, there's the idea that the holes are created when mounds of ice, covered with earth, melt. Called pingos, the loss of the ice would leave behind a big hole that collapses in on itself. Given the rising temperatures and melting of permafrost in Siberia, it wouldn't be surprising to find that pingos are melting. But, other scientists argue, these holes don't really fit the look of a pingo collapse.

But [geophysicist Vladimir] Romanovsky said the hole doesn't look like a typical collapsed pingo; such features usually form from larger mounds that slowly cave in over a period of decades, with all the material falling inside. From the photo of the Yamal crater, "it's obvious that some material was ejected from the hole," Romanovsky said. His Russian colleagues who visited the site told him the dirt was piled more than 3 feet (1 m) high around the hole's edges.

Which brings us to the other, fairly awesome, possible explanation. Some observers have noted the presence of smoke and flashes of light in the places where the holes appeared. There's also been some weirdness in the atmospheric science world with spikes of methane turning up in air over Siberia.

That's leading some scientists to speculate that the holes could be forming when methane from melted permafrost builds up in a space left by a melting pingo — eventually leading to an explosion.