Abstract
Recently, there has been a tremendous increase in the number of identified extrasolar planetary systems. Our understanding of their formation is tied to exoplanet internal structure models, which rely upon equations of state of light elements and compounds such as water. Here, we present shock compression data for water with unprecedented accuracy that show that water equations of state commonly used in planetary modeling significantly overestimate the compressibility at conditions relevant to planetary interiors. Furthermore, we show that its behavior at these conditions, including reflectivity and isentropic response, is well-described by a recent first-principles based equation of state. These findings advocate that this water model be used as the standard for modeling Neptune, Uranus, and “hot Neptune” exoplanets and should improve our understanding of these types of planets.
- Received 10 November 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.091102
© 2012 American Physical Society
Viewpoint
Seeing Deep Inside Icy Giant Planets
Published 27 February 2012
Magnetically accelerated metal plates are used to compress water to high pressures and temperatures like those inside Neptune and Uranus, permitting measurements that aid in the development of models of planetary interiors.
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