Overview
- Diamond-anvil cell and pulsed-laser heating trials at synchrotron facilities reproduced multi-gigapascal, thousands‑kelvin conditions at rocky core–hydrogen boundaries.
- Under these extremes, oxygen liberated from molten silicates combined with hydrogen to form water, while silicon formed iron–silicon alloys and silicon hydrides.
- Runs yielded water contents up to a few tens of weight percent, exceeding prior predictions for hydrogen–magma chemistry.
- The results imply hydrogen-rich sub‑Neptunes can evolve into water‑rich or Hycean‑type worlds without requiring formation beyond the snow line.
- Researchers outline observational tests for JWST and Ariel to look for water vapor, residual hydrogen, and silicon hydrides that could distinguish internally produced water.