The scientific telescopes that dethroned the Rockefeller-funded Hale reflector as the largest in the world (see 1928 entry) were also paid for by a private donor. In the mid-1980s the W. M. Keck Foundation (created by oilman William Keck) invested a total of $144 million to create two telescopes with 33-foot diameters, placed on the Mauna Kea mountaintop in Hawaii.
The first imaging at the Keck Observatory began in 1993. These two devices have brought many profound scientific discoveries. They have helped train a generation of scientists. And their very creation required groundbreaking new technologies (including advances in “active optics” that constantly shift the mirror to compensate for distortions that would compromise image sharpness) that have been spun off into other industrial uses.
- W. M. Keck Observatory, keckobservatory.org