Bladed Terrain on Pluto: Possible origins and evolution

Bladed Terrain on Pluto consists of deposits of massive CH₄, which are observed to occur within latitudes 30° 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.