By Mark Sinclair


The ‘Western Arabia Terra’ map, which covers a 3,672 x 2,721 km extent of the Mars surface, has been constructed using NASA open data ( and is available to download from the Ordnance Survey Flickr page, here. It has been produced to a scale of 1 to 4 million and was created by OS cartographic design consultant, Chris Wesson.

“We have set out from the start to treat the Mars data no different to how we would treat OS GB data or any other Earth-based geography,” says Wesson. “Even though the principles are the same, the design and the aesthetics of an Earth map differ considerably. The cartographic style is something that is very different to your typical planetary map and is identifiable as an OS map.”

The full Western Arabia Terra map

With both space agencies and the private sector looking to land the first human on the red planet, the increasing familiarity of our nearest planets is something the OS are keen to be a part of, says David Henderson, the agency’s director of products. “The opportunity to apply our innovative cartography and mapping trade-craft to a different planet was something we couldn’t resist,” he says.

“We were asked to map an area of Mars in an OS style because our maps are easy to understand and present a compelling visualisation, and because of this we can envisage their usefulness in planning missions and for presenting information about missions to the public.”

Detail from the Western Arabia Terra map

This year, the OS celebrates 225 years of mapping. According to the agency, each day over 10,000 changes are made to its database of more than 450 million geographic features.

The Western Arabia Terra map of the Martian surface is available here as a 67mb file (and at smaller sizes).

mars4-blogDetail from the Western Arabia Terra map, at full zoom
mars5-blogDetail from the Western Arabia Terra map showing the relative location of the extent covered

Read more here:: Ordnance Survey maps Mars at 1:4,000,000