The enormous installation has been built into the Roden Crater, which Turrell acquired in the 1970s. After consulting with astronomers, Turrell excavated parts of the Crater so a series of tunnels and apertures would align with celestial events that are visible to the naked eye. The Roden Crater has essentially been transformed into an artistic conservatory designed to allow the “spaces to perform a ‘music of the spheres’ in light”, according to the artist (rodencrater.com/celestial-events/).

Roden Crater Bowl (courtesy of rodencrater.com)

East Portal (courtesy of rodencrater.com)

Crater’s Eye (courtesy of rodencrater.com)

Crater’s Eye (courtesy of rodencrater.com)

Alpha (East) tunnel (courtesy of rodencrater.com)

Turrell studied and adapted essential features of other naked eye observatories around the world, including Jantar Mantar in Jaipur, India, when designing the Roden Crater. The artist considers the observatory to be a culmination of his lifelong research and work in the field of human visual and psychological perception. This piece has been in the making since the 1960s and is Turrell’s magnum opus.

Sun Moon Chamber (courtesy of rodencrater.com)

The installation consists of many spaces, each of them playing their own symbolic role in the ensemble. For example, the Alpha Tunnel, the Sun and Moon Chamber and the East Portal, which run through the center of the crater, act in concert as a Camera Obscura. In the days leading up to the winter solstice, the Camera Obscura is used to image the southernmost sunset for the year. A custom ground glass lens is used to sharpen the image. The South Space, which lies near the southern border of the Crater, is aligned with the North Star and acts as a calendar for the celestial events occurring within the 18 year 11 day Saros Cycle. You can explore an interactive online map (rodencrater.com/spaces/map/) of the installation.

Winter Solstice Event recorded at Roden Crater on December 11, 2012

Roden’s Crater was closed for a long time. Turrell fundraised to complete the project and succeeded to get $30m. He was also given $10m by Kanye West. The artist is working now with Arizona State University  toward the Land Art project’s completion to make it available for public viewing. The goal is to raise at least $200m within the next two years for elements including a visitors center, a restaurant,  cabins, and a “light-spa”. It is planned to finish Roden Crater within five years, the university says.