PSJC #130 November 30 2012

William Reach (SOFIA)

SMOG Check for Comets

Comets are well-known as mixtures of ice and solid material, with their mass loss being driven by sublimation of ices as they are warmed by the Sun. Water is the most abundant molecule and has long been thought to be the driver of cometary activity. We now know that some comets are driven by CO and others by CO2. I will describe a survey of comets at 3.6 and 4.5 micron wavelengths that measured the amount of CO+CO2 and its distribution around a set of comets. We identify a class of comets that is "CO2 rich", and we discern a wide variety of structures including jets, spirals, and a loop structure.