Garradd and M71
years ago, while cruising idly along the background of the Milky
Way, the faint Comet Garradd paid a visit to the pretty little
globular star cluster M71 in Sagitta. I took a number of
4-minute exposures to make a brief time lapse movie, and the
comet moved perceptibly between each frame. Its blue-green coma
and tail results from the fluorescence of the gas cyanogen.
The next image shows how far the comet moved in just one day.