Scientists have discovered the largest river running through Earth's core: a 260-mile wide jet of lava that flows between Canada and Russia, reports New Scientist.

The stream of molten iron was found thanks to the combined monitoring power of the European Space Agency’s trio of satellites, called Swarm, which were launched in 2013. The system keeps an eye on Earth's magnetic field and can measure as deep as about 2000 miles below Earth's surface, which is right about where the molten river was discovered.

“It’s a remarkable discovery,” said Phil Livermore of the University of Leeds, U.K., who led the team. “We’ve known that the liquid core is moving around, but our observations haven’t been sufficient until now to see this significant jet.”

The stream flows at a pace of about 28 miles per year, westward from Canada, across Alaska and into Siberia. Its movement was tracked by studying how the liquid iron affected the behavior of the magnetic field around it.

“As the iron moves, it drags the magnetic field with it,” explained Livermore. “We can’t see the flow of iron itself, only the motion of the flux lobes.”

The scientists believe the molten river is moving faster than it used to, and that its pace is accelerating, but it's unclear why the acceleration is taking place.

Andy Coghlan over at New Scientist goes into more detail about this phenomenon, and if you want to learn more, check out the abstract from the original research.