What created this enormous spiral in the Martian north pole? Wind. And Time.

In some ways, the north pole of Mars is like Earth's. Brutally cold, covered in water ice, yet chillingly beautiful. A big difference is that Earth's arctic area is ocean, while that of Mars is built up on solid ground.

Another big difference is that the Martian north polar cap has an enormous spiral-shaped trough system in it, covering an area of a million square kilometers — 50% bigger than Texas.

The Martian north polar ice cap has a spiral trough pattern in it, possibly due to erosion. Thi...