New Scientist Default Image

Extreme heat from the sun is baking a thin crust on Mercury’s surface

The sun and Mercury (not to scale)

Panther Media GmbH / Alamy

Mercury’s surface may be covered in a very thin, baked crust created by the extreme heat from the planet’s proximity to the sun.

Like Earth’s moon, Mercury’s surface lacks a substantial atmosphere, meaning impacts should break down its surface into a thin powder over time. However, Mikhail Kreslavsky at the University of California, Santa Cruz, and his colleagues have found a key difference between the two bodies.

The team looked through thousands of images of Mercury’s surface taken by NASA’s Messenger spacecraft …