Flandrau Science Center & Planetarium

Grace Flandrau never set foot in Tucson, but her estate's bequest—more than $800,000 in 1972—made the science center possible. The University of Arizona Board of Regents approved the gift that year, and three years later, in 1975, the building opened on the campus mall. The university named it after the donor, an American author whose money launched what would become one of the region's most accessible portals to the night sky.

The planetarium seats 146 people beneath a dome fifteen meters across. For decades, a mechanical star projector nicknamed "Hector Vector" handled the shows—gears and lenses throwing constellations onto the curved ceiling. That machine is gone now. In 2017, after renovations, the theater reopened as the Eos Foundation Planetarium Theater, equipped with newer digital systems that project onto the full dome. The technology changed; the function did not.

The science center houses exhibits on Earth and space sciences. The Eos Foundation mineral collection is here—specimens that document what the ground beneath Arizona is made of. The building includes a public observatory telescope, open after dark when the schedule allows.

The facility marked its fiftieth anniversary in December 2025. Fifty years is long enough to see generations of Tucson schoolchildren pass through, long enough for the building itself to become part of the university's landscape. A minor planet—18368 Flandrau—carries the center's name, a piece of formal nomenclature that ties a philanthropist who never visited to a patch of rock orbiting the sun.

The center opens Tuesday through Sunday. If you're on campus and the doors are open, the exhibits and the dome are there—no reservations required, just the cost of a ticket and the willingness to look up.