J. M. Moore, A. D. Howard, O. M. Umurhan, O. L. White, P. M. Schenk, R. A. Beyer, W. B. McKinnon, J. R. Spencer, K. N. Singer, W. M. Grundy, A. M. Earle, B. Schmitt, S. Protopapa, F. Nimmo, D. P. Cruikshank, D. P. Hinson, L. A. Young, S. A. Stern, H. A. Weaver, C. B. Olkin, K. Ennico, G. Collins, T. Bertrand, F. Forget, F. Scipioni, and New Horizons Science Team. Bladed Terrain on Pluto: Possible origins and evolution. Icarus, 300:129-144, 2018. [ bib | DOI | ADS link ]
Bladed Terrain on Pluto consists of deposits of massive CH4, which are observed to occur within latitudes 30deg of the equator and are found almost exclusively at the highest elevations ( 2 km above the mean radius). Our analysis indicates that these deposits of CH4 preferentially precipitate at low latitudes where net annual solar energy input is lowest. CH4 and N2 will both precipitate at low elevations. However, since there is much more N2 in the atmosphere than CH4, the N2 ice will dominate at these low elevations. At high elevations the atmosphere is too warm for N2 to precipitate so only CH4 can do so. We conclude that following the time of massive CH4 emplacement; there have been sufficient excursions in Pluto's climate to partially erode these deposits via sublimation into the blades we see today. Blades composed of massive CH4 ice implies that the mechanical behavior of CH4 can support at least several hundred meters of relief at Pluto surface conditions. Bladed Terrain deposits may be widespread in the low latitudes of the poorly seen sub-Charon hemisphere, based on spectral observations. If these locations are indeed Bladed Terrain deposits, they may mark heretofore unrecognized regions of high elevation.