Planets rich in carbon, including so-called diamond planets, may lack oceans, according to NASA-funded theoretical research.
Our Sun is a carbon-poor star, and as result, our planet Earth is made up largely of silicates, not carbon. Stars with much more carbon than the Sun, on the other hand, are predicted to make planets chock full of carbon, and perhaps even layers of diamond.
By modeling the ingredients in these carbon-based planetary systems, the scientists determined they lack icy water reservoirs thought to supply planets with oceans.