In Alaska, thousands of mysterious lakes are all the same shape and have grown steadily for thousands of years, the geological record shows. They are the fastest growing lakes known in the world.

Scientists have tried various ideas to explain the steady growth -- the lakes expand up to 15 feet every year -- and the lakes' consistent shape and orientation, but no theory has held up.

Now a scientist who has worked previously on puzzles as wide-ranging as the spiral shape of Mars ice caps says he's solved the terrestrial mystery.

The solution might also help explain a series of oddly similar lakes near the U.S. East Coast.