High pressure studies of solid methane were performed using diamond anvil cells in the pressure range of 0.5-86 GPa. X-ray diffractometry and Raman spectroscopy revealed two high pressure phases above 35 GPa. The results suggested that the observed high pressure phases have a fundamental structure similar to that of a reported high pressure phase, but they exhibit the orientational ordering of molecules in a different manner. An intermediate metastable phase was found between known phase A and phase B, which showed a structure close to that of phase B but showed rotation of molecules close to that of phase A. (c) 2008 Elsevier B. V. All rights reserved.