The USGS is amazing. They have incredibly detailed information for the US: elevation (within 10 ft in many places), demographics, geology, and others. They have an amazing geologic map for Big Bend National Park [1] (a very geologically interesting park in southern Texas). Global maps are a lot harder to come by, unfortunately, although I did find a similar geologic map of the Earth as the one for Mars (divided by pieces) at [2].<p>[1] <a href="http://pubs.usgs.gov/sim/3142/" rel="nofollow">http://pubs.usgs.gov/sim/3142/</a><p>[2] <a href="http://energy.usgs.gov/OilGas/AssessmentsData/WorldPetroleumAssessment/WorldGeologicMaps.aspx" rel="nofollow">http://energy.usgs.gov/OilGas/AssessmentsData/WorldPetroleum...</a>
This map is certainly very interesting, but it suffers as a visualization. The topographical map is nice, due to its simplicity and well-chosen color scale, but the main geological map certainly has some problems.<p>The biggest problem is that they are choosing two represent two different dimensions of data(age/time period and terrain type), but are using seemingly random variations of hue to show these variations. Additionally, with so many distinct hues, it is nearly impossible to tell the difference between some areas on the map (for example, Hesperian basin unit and Hesperian polar look very similar).<p>A more effective way to visualize this data would be to apply a separate hue to the 8 categories of terrain unit, since these are categorical data points. Then, visualize the geological age on a brightness scale, since this is more of a quantitative measurement (obviously the current map also show the particular time period, we'll just ignore that for now). I think this would provide a much clearer view of the data, though you would lose a small bit of granularity.
Watching the individual shapes render on the PDF in Firefox's PDF viewer reminded me of fond memories of DOS-based mapping software I had as a kid on an 8MHz 8088 PC-XT with CGA graphics. Once upon a time, you actually had to wait for each individual vector shape to be drawn :-).<p>Edit: maybe this comment should have been a reply to <a href="https://news.ycombinator.com/item?id=8046656" rel="nofollow">https://news.ycombinator.com/item?id=8046656</a>
This is lovely, would probably make a nice print! I'm working my way through Kim Stanley Robinson's Mars trilogy; this makes a great accompaniment.
I am particularly fascinated by the small topological map. I like imagining what Mars would be like under Earth-like conditions - if a watery planet looked like that, how would people live? Where would the population be most concentrated? How would the political landscape be influenced by the geography?<p>I guess I spent too much of my childhood playing Role Master :-)