Charles Ross is one of the many land artists who emerged in the late 1960s/early 1970s and created site specific natural art works using whatever media they could find or build. Ross differed from many of the other land artists though, as his interests lie in science and physics. He utilises his scientific knowledge to create aesthetically pleasing art work, such as a light spectrum of colours we see in a rainbow.
Built in 1971, in New Mexico, 'Star Axis' by Ross is a sculpture/structure which extends our environment into the night sky and the stars. From different angles and areas of the sculpture you can witness different wonders of our universe. You can view daily and seasonal movements of our sun, you can view the rotation of the earth, the stars which are visible from near the equator, you can also see thousands of years of the axial precession of the earth in the 'Star Tunnel'. The whole sculpture is precisely in line with the earth's axis, as it points towards the North Star, Polaris.
I find this particularly artwork fascinating. It is almost not an art work, more a scientific tool, or observatory of sorts. I feel this work is a kind of planetarium, but the largest scale possible planetarium or observatory you could find, as it allows you to view the real stars millions of miles and light-years away.