A Planet Once Thought to Be Made of Diamond

55 Cancri e is a super-Earth twice the size of our planet, and for years it was called a diamond world. Early studies suggested a carbon-rich interior, where intense pressure could turn carbon into diamond. But observations from the James Webb Space Telescope in 2024 point to something different: a rocky, magma-covered planet wrapped in a thick atmosphere rich in carbon dioxide or carbon monoxide, with a temperature of about 2,000 K (roughly 1,700°C). Whatever is down there, you wouldn’t want to go mining on it.