In my review of Paul Schenk’s Atlas of the Galilean Satellites I noted that the maps of Jupiter’s four largest moons were actually spacecraft imagery placed on a map projection; there were no non-photographic maps. In that context, the geologic map of Io, just out from the U.S. Geological Survey, is both novel and pertinent. The maps are based on Voyager– and Galileo-derived photomosaics of Io’s surface released in 2006, but they’re maps. ASU news release, Universe Today.
Ars Technica calls Old Maps Online “the world’s single largest online collection of historical maps” but that’s not strictly the case. When I first read that I thought: what, bigger than Rumsey? Rumsey has 30,000 maps; Old Maps Online has 60,000. But Old Maps Online is a portal, not a collection: it has a damn slick timeline-and-map interface that brings up maps from the online collections of five institutions (so far), including the British Library, the National Library of Scotland, and yes, the David Rumsey Map Collection. At first glance it seems like a good place to start if you’re looking for a map of a specific time and place (as I have done on many occasions), and if they add more institutions to their database it will be even more useful.
Fantasy maps have a very specific style that is actually quite limiting. For an example of what would happen if all maps were subject to the same limitations as fantasy maps, have a look at what is described “a map of the United States à la Lord of the Rings”; it was posted to Reddit and edited there by divers hands. The version above had the gridlines removed and made more “antique.” It does look like the early Middle-earth maps done by Pauline Baynes and Christopher Tolkien. To match the movie maps, you’d have to replace all the text with overdone uncial calligraphy and Tengwar vowel marks, whereas maps in modern fantasy novels would lose the shading on the mountains and have all the text done in Lucida Calligraphy. Via io9.
Paul Schenk’s Atlas of the Galilean Satellites (Cambridge University Press, 2010) collects all the imagery gathered by the Voyager and Galileo missions of the four major moons of Jupiter (Callisto, Ganymede, Europa and Io, all discovered by Galileo in 1610) and assembles them into global, quadrangle and area maps. But this heavy, 400-page tome begins with a confession. “This Atlas is not what it should be.” The failure of the high-gain antenna on the Galileo spacecraft meant that far less data could be transmitted back to Earth during its nearly eight-year mission than had been planned. Large tracts of the moons are mapped in low resolution; the fuzzy images yield little detail. But until another mission is sent—the Juno probe now en route to Jupiter will not be studying the moons—this is all there will be for the foreseeable future. For decades, in fact.