Extensional Faults on Pluto (IMAGE) University of California - Santa Cruz Caption Extensional faults (arrows) on the surface of Pluto indicate expansion of the dwarf planet's icy crust, attributed to freezing of a subsurface ocean. Credit NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Alex Parker Usage Restrictions For use only with news coverage of this research License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.