The moon at 850 microns

On the night of July 15, 2000 Jane Greaves mapped the moon using SCUBA's fast scan mapping. The initial results were so much fun that Iain Coulson and Nick Jessop decided to repeat it 6 nights later. The resulting images (reduced using a slightly modified version of ORAC-DR) are shown above. Tim Jenness helped a lot in the data processing.

What does it mean? At 850 microns the emission is due to thermal emission from the top centimetre or so of the moons surface. It is not due to reflection as in visible images. The emission is from a modified black-body function. Due to the fact that the emission is from the Rayleigh-Jeans tail, to a first approximation the brightness is proportional to the temperature. The image is a temperature map of the moons surface! We're hoping the weather gets bad enough that we can map a couple more phases of the moon (these images were taken on 2 nights when the telescope would ordinarily have been closed due to the poor conditions).