During a span of 40 years, since 1972, the Landsat series of Earth observation satellites has become a vital reference worldwide for understanding scientific issues related to land use and natural resources.
Beyond the scientific information they supply, some Landsat images are simply striking to look at, presenting spectacular views of mountains, valleys and islands, as well as forests, grasslands and agricultural patterns. By selecting certain features and colouring them from a digital palate, the US Geological Survey has created a series of ‘Earth as Art’ perspectives that demonstrate an artistic resonance in satellite land imagery and provide a special avenue of insight about the geography of each scene.
Nasa asked the public to vote on their favourite images from the more than 120 images in the online “Earth as Art” collection – and received over 14 000 votes.
This image of Erg Iguidi in Algeria taken by Landsat 5 took 4th place. The image was acquired on 8 April 1985.
What look like pale yellow paint streaks slashing through a mosaic of mottled colours are ridges of wind-blown sand that make up Erg Iguidi, an area of ever-shifting sand dunes extending from Algeria into Mauritania in northwestern Africa. Erg Iguidi is one of several Saharan ergs, or sand seas, where individual dunes often surpass 500 metres in both width and height.
Image credit: Nasa’s Goddard Space Flight Centre/USGS)