“Originally, it was thought that water and rock layers in water-rich planets were well-separated,” Nisr said. “But we discovered through our experiments a previously unknown reaction between water and silica and stability of a solid phase roughly in an intermediate composition. The distinction between water and rock appeared to be surprisingly 'fuzzy' at high pressure and high temperature.”

The researchers hope that these findings will advance our knowledge on the structure and composition of water-rich planets and their geochemical cycles.

“Our study has important implications and raises new questions for the chemical composition and structure of the interiors of water-rich exoplanets,” Nisr said. “The geochemical cycle for water-rich planets could be very different from that of the rocky planets, such as Earth.”

In addition to Nisr and Shim, co-authors from ASU include alumni Huawei Chen; Kurt Leinenweber of ASU’s Eyring Materials Center; and Andrew Chizmeshya of ASU’s School of Molecular Sciences. Additional researchers on the team represent the University of Chicago, University of Cologne (Germany), Argonne National Laboratory (Illinois) and George Washington University (Washington, D.C.).

Karin Valentine

Media Relations & Marketing manager, School of Earth and Space Exploration