RAO CMT installation

50 Years of Discovery

Learn more about our 50 year amazing journey

Constructing the CMT pier


Key events that marked 50 years of development

ARCT test

RAO People

People who shaped and built the RAO

Comet Hale Bop 1994

Technology and Research

Technology advancements that aided in research over the past 50 years

50th Anniversary

50th Anniversary RAO


On January 7th, 1972, the inauguration of the Rothney Astrophysical Observatory began a journey of research, science education and dark sky advocacy in Southern Alberta. The observatory is owned and operated by the Science faculty and has developed as research facility and outreach centre for the University of Calgary.

The official opening occurred on a very cold morning January 7, 1972, next to the .4 metre telescope dome. This telescope is now named after observatory founders Alan Clark and Eugene Milone. The dedication ceremony was attended by Dr. Margaret Burbidge, Astronomer and Director of the Royal Greenwich Observatory and she unveiled a sundial to mark the official opening.

In 1969, Dr Alan Clark was tasked with locating a place for students from the newly established Physics and Astronomy department to observe the night sky. He explored the possibility of using the Photographic Zenith Tube Observatory that was located southwest of Calgary. A Canadian government observatory, Dr Clark visited the site and was awed by the spectacular south - southwest aspect of the hill near the site. The land was owned by Alexander Rothney Cross ‘Sandy’, who was the grandson of A. E. Cross one of the big four founders of the Calgary Stampede. Initially, a possible purchase of an acre of land was discussed the land agent, Joe Fisher, in Turner Valley. However, when Sandy learned about the plans for an observatory, he offered a quarter section of Cross land as a gift to the University of Calgary.  

The honour of naming the observatory was left to Sandy Cross. He proposed the name Rothney, which is a family name from his grandmother Helen Rothney Macleod (1878-1959). Throughout the Rothney Astrophysical Observatory 50 years of operations the observatory has been the fortunate beneficiary of four major funding and land gifts from the Cross family. They have been patrons of the university and of science and education and generations of students at all levels have benefited from Sandy's generosity and that of his family.