NASA spacecraft discovers a 10-mile thick layer of diamond on Mercury

The solar system's tiniest planet may be hiding a big secret. Using data from NASA's MESSENGER spacecraft, scientists have determined that a 10-mile-thick diamond mantle may lie beneath the crust of Mercury, the closest planet to the sun. This new study also relates to a major surprise that came a few years ago when scientists re-evaluated the distribution of mass on Mercury, discovering the mantle of this tiny planet is thicker than previously thought.