[dnlk]

i just love the fact that with all the really expensive (so i believe) hardware and software he used, this really stood out to me:

"GIMP: final assembly, curve & saturation tweaks" (from his website skysurvey.org)

[timerickson]

I was curious what software would be powerful and flexible enough to stitch together 37,000 photos. Clearly GIMP is the choice for that job.

[markbnine]

Mosaics that include far more photos are made all the time using spacecraft data. One of the software packages of choice is ISIS: http://isis.astrogeology.usgs.gov/