OBSERVATION / 001

The Eye of the Sahara.

NASA Earth Observatory / Lauren Dauphin · Landsat / USGS

Location

Richat Structure / Mauritania

Image acquired

March 5–6, 2026

Platform / instrument

Landsat 9 + Landsat 8 / OLI

Image type

Satellite mosaic

Field notes

A ring of concentric ridges, roughly 40 kilometers across, stands out against the desert of Mauritania’s Adrar Plateau. Its geometry is much easier to recognize from orbit than from the ground.

The resemblance to an impact crater led to an early explanation that was later overturned. NASA describes the Richat Structure as an uplifted geologic dome, worn down at different rates as its layers of rock eroded.

This is dated source imagery. The homepage overlay is a graphic treatment, not a georeferenced measurement.