Does pluto have a substantial atmosphere?

Abstract

The presence of CH 4 ice on Pluto implies that Pluto may have a substantial atmosphere consisting of heavy gases. Without such an atmosphere, sublimation of the CH 4 ice would be so rapid on a cosmogonic time scale that either such an atmosphere would soon develop through the exposure of gases trapped in the CH 4 ice or else the surface CH 4 ice would soon be all sublimated away as other, more stable, ices became exposed. If such stable ices were present from the beginning, the existence of CH 4 frosts would also imply that Pluto's present atmosphere contains a remnant of its primordial atmosphere.