Pluto's "Thick" Air Isn't Going Anywhere

astroengine writes "When the proposition for NASA's New Horizons mission to Pluto was put forward, there was an air of urgency. The dwarf planet is moving away from the Sun in its eccentric orbit, so astronomers were concerned that the Plutonian atmosphere would freeze out and collapse onto the surface as fresh nitrogen-methane snow before they could get a spacecraft out there to observe it. But according to new research [arXiv], it appears there's little risk of a Pluto air freeze-out. From recent occultation measurements, it appears the atmosphere is becoming denser and more buoyant, meaning it will remain as an atmosphere all (Pluto) year 'round — 248 Earth years long."