Web mapping uses Web Mercator. As Kenneth Field points out, this is fine at large scales, but at small scales you end up replicating the problem of using the Mercator projection on a wall map of the world.1 Zoom out in Apple Maps: using the map layer you get a Mercator; using imagery you get a virtual globe (basically, an orthographic projection you can spin). Ditto in Google Earth. But Google Maps, after some tests and starts, now does this in its map layer—and not just in Chrome, either. This means, among other things, that Antarctica is usably visible, as are the Arctic regions—and, of course, Greenland is its proper size at small scales.
The University of Lausanne has come across a pair of globes—one celestial, one terrestrial—made by Mercator in the 16th century. Mercator apparently had a reputation as a globemaker, and a number of his globes are still in existence today. But “not particularly rare” is not the same as “not particularly interesting,” and the globes, which first turned up on campus in 2004, are now the subject of an exhibition at the Espace Arlaud in Lausanne, which runs until 15 July, and an extensive and detailed website that talks about the globes and how they were discovered and authenticated. Digital versions of each globe have also been produced: here’s the terrestrial globe; here’s the celestial globe.
All of this, by the way, is in French. If reading French is not your thing, the Harvard Map Collection also has a pair of Mercator globes, which you can view via their (rather dated) website.
The David Rumsey Map Collection has a number of virtual globes, but its AR Globe app may be the most unusual way to view them. Released last December for the iPhone and iPad, it uses augmented reality to superimpose one of seven celestial or terrestrial globes from the 15th through 19th centuries. The globes can be manipulated—spun, zoomed in and out—or observed from the inside (which is a good thing with celestial globes).
To be honest I’m not sold on using augmented reality to view virtual globes. It’s one thing to use AR to superimpose IKEA furniture in your living room: that makes sense, because it helps you visualize where the furniture would go and what it would look like. But it’s hard to see the utility of plunking a virtual globe in your living room: what’s the point of adding your surroundings as a backdrop? Case in point:
It’s neat but not particularly useful, is what I’m saying.
Meridian, an “experiment” from the DX Lab at the State Library of New South Wales, overlays old maps onto virtual, 3D interactive globes. Two globes have been created to date—one based on the 1706 Miranda world map (previously), the other on a set of Coronelli globe gores from 1693—with more in the works. Details here. [Cartophilia]
The Moon and Mars were relatively early additions to Google Earth; that application may have been migrated to the web, but the planets and moons keep coming. Yesterday Google announced the addition of a dozen other worlds in our solar system; the space layer of Google Maps now includes planets Mercury, Venus and Mars; dwarf planets Ceres and Pluto;1 Jupiter’s moons Io, Europa and Ganymede; and Saturn’s moons Dione, Enceladus, Iapetus, Mimas, Rhea and Titan. Large moons Callisto and Triton aren’t included, and Iapetus is projected onto a sphere rather than appearing as the bizarre space walnut it is.
The Planetary Society’s Emily Lakdawalla noticed a thing, though:
Anybody know who I should talk to at @Google to let them know that several of the icy moon maps have names & image offset by 180 degrees?
— Emily Lakdawalla (@elakdawalla) October 16, 2017
Emily reports that this bug affects several moons of Jupiter and Saturn; Google is apparently already on it and may have fixed it by the time you read this.