There Is a Planet Made Entirely of Diamond

Orbiting a star just 40 light-years away is a "super-Earth" that redefines planetary composition. Officially designated 55 Cancri e, this exoplanet is thought to be a carbon world, a stark contrast (Review) to Earth's silicate-rich makeup. The theory stems from its host star, which has a much higher carbon-to-oxygen ratio than our sun. Scientists believe that as the planet formed from the same stellar nursery, it incorporated vast amounts of carbon. Under the incredible heat and pressure of its interior, this carbon would have been compressed into a massive, planet-sized diamond.

While the idea of a world glittering with riches is captivating, the reality is far from hospitable. 55 Cancri e is tidally locked, meaning one side perpetually faces its star, with surface temperatures hot enough to melt metal. Its surface is likely a dynamic landscape of graphite and other carbon compounds, with a deep, dense mantle of pure diamond beneath. This incredible diamond layer could account for up to a third of the planet's total mass, giving it a theoretical value of $26.9 nonillion. This celestial treasure chest serves as a stunning example of the incredible diversity of worlds that exist beyond our solar system.