NAM2011 Presentation Details
Discovery of Carbon Monoxide in the Upper Atmosphere of Pluto
Author: Jane Greaves
Co-Authors: Ch. Helling (University of St Andrews); P. Friberg (Joint Astronomy Centre)
Session: RAD: Radio window on the solar system
Presentation type: Talk
Only one molecule, methane, has ever been detected in Pluto's thin and fragile atmosphere. Carbon monoxide is also expected, sourced from evaporation of surface ice, and acting as the key coolant. Using the JCMT in 2009/10, we detected the millimetre-wave CO 2-1 rotational transition, at a brightness requiring that the gas extends into the cold upper atmosphere, as high as three Pluto radii above the surface. Compared to an upper limit from 2000, the line-centre signal is at least twice as bright. This implies the atmosphere has significantly altered in composition or size over only a decade, in a striking example of extraterrestrial climate change.