A Heart of Ice: Frozen Carbon Monoxide in Tombaugh Regio

Carbon monoxide on Pluto has been observed from Earth before, but a new overlay of data collected on July 14 by the composition mapping spectrometer on the Ralph instrument, has pinpointed its location for the first time.

The frozen carbon monoxide is concentrated spatially on the western side of the heart, informally known as Tombaugh Regio. Overlaid with contours, the map shows the abundance of carbon monoxide increasing towards the centre of the “bull’s eye”.

The thickness of this layer is unknown, but the contours indicate that its thickness increases towards the center of the deposit. At the July 17 press conference, Will Grundy, the New Horizons Surface Composition team leader, pointed out that only a thickness of a centimeter is required to produce absorption, this layer may be thicker.

Scientists do not know why frozen carbon monoxide is concentrated in this specific area or what its origins might be. One possibility is that there could be a source region and the science team will be looking for it when images with 7x the resolution are downloaded from New Horizons.

This observation caught the eye of the science team since there are no other areas on this side of Pluto that show this type of carbon monoxide concentration.

Pluto is indeed a special place, full of surprises. As Alan Stern, Principal Investigator for the New Horizons mission said, "I’ m a little biased but I think the solar system left the best for last."