The Nardò Ring is a striking visual feature from space, and astronauts have photographed it several times. The Ring is a race car test track; it is 12.5 kilometers long and steeply banked to reduce the amount of active steering needed by drivers. Although it is a perfect circle, it appears oval in this photograph. This distortion is because the astronaut’s viewing angle was 35 degrees, looking back along the orbit track to the southwest from the International Space Station’s window.
On May 20, 2008, a deck of clouds over the Pacific Ocean provided an optical display for the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. The ring-shaped, rainbow-like phenomenon, known as a glory, appears through the length of the center of this image.
In eastern Siberia, a perfect circle of rock contrasts with the surrounding topography. The 6-kilometer- (3.7-mile-) wide ring looks like an impact crater, or the caldera of an extinct volcano, but it is neither. Kondyor Massif was formed by the intrusion of igneous, or volcanic, rock that pushed up through overlying layers of sedimentary rock, some of them laid down more than a billion years ago.
A dry river channel carves through the Zagros Mountains in southern Iran and spreads out across the valley floor in a silvery fan. A broad belt of lush agricultural land follows the curve of the alluvial fan.