Mercury is a small, dense planet with a large metallic core and a thin crust. Its surface is cratered and volcanic, and it has a magnetic field and a weak atmosphere.

Mercury is the second densest planet, after Earth. It has a large metallic core with a radius of about 1,289 miles (2,074 kilometers), about 85% of the planet's radius. There is evidence that it is partly molten or liquid.

Learn about Mercury, the innermost planet of the solar system, and its surface features, composition, and history. Find out how Mercury's density, core, and craters differ from the Moon and other planets.

A comprehensive overview of Mercury's physical and orbital parameters, observational history, magnetosphere, atmosphere, and surface features. Includes bulk and orbital comparisons with Earth, and data sources and references.

Learn about the innermost planet in our solar system, its origin, surface, and missions. Mercury is a terrestrial planet with a dense metallic core, a rocky mantle, and a solid crust.

Mercury - Craters, Volcanoes, Plains: Messenger used X-ray fluorescence spectra to study the surface composition of Mercury. It found a high ratio of magnesium to silicon and low ratios of aluminum and calcium to silicon, which showed that the crust was not rich in feldspar like that of the Moon.

The geology of Mercury is the scientific study of the surface, crust, and interior of the planet Mercury. It emphasizes the composition, structure, history, and physical processes that shape the planet.