Pluto appears to trail a wispy carbon monoxide cloud
Just like Mickey’s dog, the former planet Pluto has a tail — or at least a hint of one.
Scientists have detected a wisp of carbon monoxide in Pluto’s thin upper atmosphere, extending a quarter of the way to its largest moon, Charon, or about 3,400 kilometers above Pluto’s surface. To the astronomers who detected it using the James Clerk Maxwell Telescope on Hawaii’s Mauna Kea, the cloud appears to have properties resembling a comet’s gas tail.
“Whether Pluto's atmosphere forms a tail is just a suggestion on our part,” says Jane Greaves of the University of St. Andrews in Scotland. The gas is too thin to image directly. But a tiny shift in the wavelength of microwaves emitted by the carbon monoxide hints that the gas is receding from Earth and the sun, with ions and some neutral atoms in the gas swept up by the solar wind — just as a comet’s gas tail would be.
Planetary scientist Mike Brown of Caltech