Mercury's crust is extremely thin. It is probably thinner than Earth's. Above the surface, Earth and Mercury are very different. Earth's atmosphere extends hundreds of miles above the surface. Mercury has almost no atmosphere at all.
Mercury is much closer to the Sun than Earth is. From Mercury, the Sun looks almost three times larger than it does on Earth. Mercury is so close to the Sun its daytime temperature can reach 870¬°F (467¬°C). There is no atmosphere to hold the heat. At night, Mercury cools quickly. The temperature can drop to -297¬°F (-183¬°C).
