Mr. Alexander (Sandy) Rothney Cross donated a quarter section of land to the University in 1970. At Cross’s request the observatory was named the Rothney Astrophysical
Observatory to honour his mother’s side of the family. The site was officially opened in January 1972 with an unveiling of a sundial to symbolize the emergence of the University of Calgary onto the astronomical scene.
When the Observatory opened, the site consisted of a dome to house the 0.4 m telescope, and an ATCO trailer to house equipment, and to double as a teaching area. In 1983, a Baker-Nunn satellite tracking camera was bought for $.01 and transferred to the RAO from the Canadian Forces base at Cold Lake. Also in 1983, the ground was broken for a new observatory building and dome to house the Baker-Nunn, the new 1.5 m infrared telescope, and an aeronomy laboratory.
At the building opening in 1987, the 1.5 m infrared telescope was renamed the Alexander Rothney Cross Telescope (ARCT) in honour of Cross who continued to donate money to the RAO through the Cross Educational Foundation. In the late 1980s, the Astrophysical Research Consortium at the Apache Point Observatory in New Mexico offered to fund half the costs of polishing a mirror for a 1.8 m telescope in exchange for its short-term use. The new 1.8 telescope and mirror were installed in the mid-1990s and “first light” was achieved in January 1996. A year later, the RAO celebrated its 25th anniversary.
The RAO continued to expand with a new Visitor’s Centre and teaching facility that opened in 2005. The current facility houses research, teaching and community programs with Open Houses and events throughout the year. The RAO has grown from an empty pasture to become a million-dollar research destination.