Since 1972, artist James Turrell has been transforming Roden Crater in Arizona’s Painted Desert into a huge piece of art. 

The extinct, 400,000 year-old, 600-foot tall volcanic cinder cone sits at an elevation of about 5,400 feet above seal level, pretty close to the Grand Canyon. It's impressive on it's own, for sure, but James Turrell has been on a mission for over 40 years to create a large-scale light installation within the crater.

His idea is to "bring the light of the heavens down to earth," allowing visitors to view the movement of the planets, stars and even other galaxies:

My work is more about your seeing than it is about my seeing, although it is a product of my seeing. I’m also interested in the sense of presence of space; that is space where you feel a presence, almost an entity — that physical feeling and power that space can give.

In addition to studying light and space, James Turrell also uses his art to have consider the ancient idea of "the observatory" as a place to go and see.

Who knows how long it will take for James to complete his vision, but 40 years in the making, it's certainly already an incredible feat of determination.