The Ice of Mercury
Mercury, the closest planet to our sun and the second hottest, also has glaciers. That may come as a surprise, but it’s due to the fact that the planet has no tilt, and so the bottom of some deep craters near the poles are left permanently shadowed. With no atmosphere, the planet’s night side quickly loses heat and dips far below freezing, allowing ice to form and accumulate in regions that never see the sun.

Now, new models reveal incredible details about how glaciers f