Star Dune Ridges

Star Dune Ridges is an original illustration set in Namib Sand Sea, Namibia. It lies in the subtropics, where the climate is hot desert — evaporation far outruns rainfall.

A tall central summit sends three or more sand ridges radiating outward, their sharp sinuous crests converging at the top. Alternating bright and dark triangular faces catch the light differently. Small crescent dunes sit at the base, dwarfed. The sand is deep red.

Why does a star dune grow upward instead of moving?

Star dunes need wind arriving from several directions through the year: each wind builds its own arm, and because no direction wins, the dune grows upward instead of migrating. They are the tallest dunes on Earth for exactly that reason. Deep red sand means iron oxide coatings built up over an enormous span of time — this sand has been sitting here, being reworked, for a very long while.

Terpano is a free daily geography puzzle. You study one original illustration, place a pin on a borderless terrain map, and see how close you were. There is no account and no sign-up; progress stays in your own browser. It plays in 11 languages.