satellite imager

Is this a ridge or a canyon? Relief inversion plays tricks on the brain with this image of the Colorado River in Arizona. Photo: NASA

Relief Inversion

Caitlin Dempsey

Telling the difference between a canyon and a mountain on aerial or satellite imagery can sometimes be tricky due to an optical illusion known as relief inversion.

GPS and a Grader Bring Back the Maree Man Geoglyph in Australia

Elizabeth Borneman

The Marree Man is a geolyph located in the Australian Outback. A geolyph is an image or a picture that is a design in the earth, and it is usually made of natural materials.