North Pacific loggerhead sea turtles (Caretta caretta) hatch on the shores of Japan and spend much of their time in the open Pacific, but sometimes mysteriously crop up in Mexico, 9,000 miles (14,500 kilometers) away from their original nesting ground.

That incredible journey requires them to pass through potentially deadly, cold waters that should be inhospitable to them, since loggerheads rely on warmth from the surrounding environment to maintain their core body temperatures. Now, scientists have a clue as to how the turtles survive this epic migration.