This is an image of Pluto. Click on image for full size version (128K GIF) Image from: NASA

It may seem hard to believe that Pluto could have an atmosphere because it is so cold at 39 AU, where Pluto is found, but it does. Because there are times when Pluto is closer to the sun than is Neptune (making it the 8th planet for roughly 20 years at a time), ices on Pluto's surface evaporate and form an atmosphere. It is continually produced and lost again as long as Pluto is inside Neptune's orbit.

The air is made mostly of nitrogen gas, just like that of the Earth and Saturn's moon Titan, with the addition of carbon monoxide (CO - what comes out of your car) and a molecule called methane.

The atmosphere is also similar to that of Neptune's moon Triton.. On Triton there are seasons and winds. Because Pluto has a bigger atmosphere than Triton, there may even be clouds and storms. However, seeing these clouds and winds on Pluto is difficult.

It is also possible that the presence of nearby Charon draws molecules escaping from Pluto's atmosphere to the surface of Charon, as suggested in this image. So this double planet may exchange molecules from their atmospheres.