I have a peculiar hobby of collecting Martian hypsometric tinting schemes: those sets of colors that cartographers use to depict elevations on the Red Planet. It’s a fascinating cartographic frontier. While the classic (and somewhat flawed) way of showing Earth’s elevations is to use a color scheme that starts with green lowlands, and then proceeds through some combination of brown/yellow/orange/red until it reaches white in the highest areas, there’s no standard yet for Mars. Maybe centuries from now, one of the schemes below will become that standard.
The Digital Museum of Planetary Mapping is an online collection of maps of the planets and moons of our solar system. There are more than two thousand maps in the catalogue, some dating as far back as the 17th century, but the bulk of them, understandably, are much more recent; also understandably, Mars and the Moon are the subject of most of the maps (40 and 46 percent, respectively).
The site is more like a blog than a library catalogue: it’s powered by WordPress and the individual listings are blog posts, but that’s perfectly legitimate, albeit less elegant. (But then who am I to judge?)
The project was presented at the European Planetary Science Congress in Berlin last month: for news coverage, see Phys.org and Space.com; the press release is here. [WMS/WMS]
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.
A new gravity map of Mars that shows the thickness of the Martian crust based on gravity measurements from Martian orbiters, reveals a crust that is less dense and shows less variation than earlier maps. “The researchers mapped the density of the Martian crust, estimating the average density is 2,582 kilograms per meter cubed (about 161 pounds per cubic foot). That’s comparable to the average density of the lunar crust. Typically, Mars’ crust has been considered at least as dense as Earth’s oceanic crust, which is about 2,900 kilograms per meter cubed (about 181 pounds per cubic foot).”
Concomitant with the Survey’s map of Mars was a competition to design a map symbol to represent landing sites. The winner has been announced: the OS will use Paul Marsh’s symbol, which incorporates the Mars symbol with landing gear, on its Mars maps in the future.
The project is to select one candidate landing site and design an actual map that you envision will be useful in surface operations. We ask that you do not create simply a geologic map, but rather a product that can be used by the astronauts during their approximately one-year long mission within the Exploration Zone. This requires creativity, and it is also useful to have a good knowledge of surface features, surface hazards, science goals and the use of the proper cartographic tools.
The contest is open to students, young professional cartographers, and graphic artists in any country of the world.
Kenneth Field’s map of Mars (note updated link) now includes an option to add oceans, with checkboxes to fill the landscape to various elevations.
You can irrigate the planet below the areoid on this map using the water layers. You’ll notice the water layers aren’t blue. On Earth, water appears blue due to red, orange, yellow and green wavelengths of light being absorbed more strongly than blue and also the reflectence of the blue sky. Since Mars has relatively little atmosphere and it’s farther from the sun it’s likely water will appear differently. We’re imagining wavelengths will be absorbed differently, perhaps returning an alien green?
Daniel Macháček released his topographic map of Mars, based on the latest probe data, in November 2014. It uses the Mercator projection between 65° north and 65° south latitude and stereographic projections for the poles. It can be downloaded in insanely high resolution: 17,400×14,700 (78 MB JPEG, 106 MB PDF). His blog post (in Czech: use the translate button) has all the technical details. I particularly like the colour scheme he used for elevation data: the low-lying areas are coloured like deep oceans, which seems appropriate. [Maps on the Web]
A new gravity map of Mars, based on data from three orbiting spacecraft, has been released. “Slight differences in Mars’ gravity changed the trajectory of the NASA spacecraft orbiting the planet, which altered the signal being sent from the spacecraft to the Deep Space Network. These small fluctuations in the orbital data were used to build a map of the Martian gravity field.”
The data enables the crustal thickness of Mars to be determined to a resolution of approximately 120 kilometres. Here’s a short video explaining the significance:
Another online map of Mars, this one titled (Is There) Life on Mars? and produced by Kenneth Field using ArcGIS. On the information pane he says, cryptically, “There’s a hidden element on the map that explains why I really made it. Happy hunting.” [via]
Eleanor Lutz’s map of Mars isn’t exactly medieval in style (that’s not the right word for it), but it applies an ostensibly old aesthetic to a very modern map subject. “I thought it would be fun to use their historical design style to illustrate our current adventures into unexplored territory. […] Since the base map is hand-drawn I also added an overlay of actual NASA topographic imagery. This way even if some of my lines are a little off, you can still see what the actual ground looks like underneath.” Whatever you call it, it looks amazing. [via]
The Ordnance Survey has created a map of Mars. “The one-off Ordnance Survey Mars map, created using NASA open data and made to a 1:4,000,000 scale, is made to see if our style of mapping has potential for future Mars missions.” It looks very much like a topographic map of Mars might; the reduced version is a bit more screen-friendly.
Dawn’s first colour map of Ceres: map-projected false-colour images of the dwarf planet taken as the spacecraft approached, assembled from images taken through blue, green and infrared filters. (Previously: At Ceres.)