A possible atmosphere for Pluto

At the temperature of Pluto (～43°K) the only gas which would neither condense nor escape is neon. Since neon is cosmically abundant it is suggested that Pluto may have a fairly extensive atmosphere consisting of almost pure neon. The possibility that such an atmosphere exists is analyzed, along with the possibility that oceans of liquid neon may exist at the surface.A neon atmosphere would not produce any observable absorption lines. However, if it were very thick, then Rayleigh scattering would result in Pluto having a much higher albedo in the ultraviolet than in the visual, which is not observed to be the case. This enables us to set an upper limit on the mass of Pluto's atmosphere.