We changed the URL from https://kottke.org/21/02/10-terapixel-image-of-the-night-sky to the viewer.
Another article is https://www.syfy.com/syfywire/a-billion-galaxies-lurk-in-a-1...
The FAQ is here: https://djschlegel.wordpress.com/faq-legacy-survey-sky-image...