How a Meteorite Helps Explain Mercury's Chemical Makeup

Mercury is one of the four rocky worlds of the Solar System, yet its chemistry is very different from Earth, Venus, and Mars. Missions to the planet show that it has an iron-poor, but sulfur- and magnesium-rich crust. Furthermore, it's known to planetary scientists as the most reduced planet in the Solar system. It means that the chemical makeup is dominated by sulfides, carbides, and silicides -- as opposed to oxides like we see here on Earth.