Pluto is often considered to be a ‘binary planet’ with its largest moon Charon and now it seems that both share more than a common orbit — they may also share a thin atmosphere.
This new finding arose from new models published in the journal Icarus of the Pluonian system that show gases from Pluto are being transferred to Charon. Charon has a compact orbital distance of only 12,000 miles from the center of Pluto and both bodies orbit around a common point, known as a barycenter, which is located above Pluto’s icy surface. Recent observations have shown Pluto’s thin atmosphere to be composed mainly of nitrogen and the assumption was that the gas is too heavy and too cold to escape Pluto’s gravity.
But new simulations suggest the dwarf planet’s atmosphere may be warmer and thicker than anticipated, meaning the nitrogen gas has enough energy to escape Pluto and may be exchanged to Charon and both bodies share a common atmosphere.
Should any gases be present around Charon, it is too thin to be detected by ground-based observatories. But NASA’s New Horizons mission, which is set to fly through the Pluto-Charon system in July 2015, has instruments that should be able to detect such a thin Charonian atmosphere and decipher if the gases originated from Pluto.
“(Gas transfer is) thought to happen all the time in astronomy, such as in the case of binary stars or exoplanets located close to their stars,” Robert Johnson, of the University of Virginia in Charlottesville, told New Scientist. “Calculations and computer models are one thing. But here we have a spacecraft that’s going to fly by and directly test our simulations, which is quite exciting.”
Source: New Scientist