Day 21: Elevation –Olympus Mons, Mars

Map of Olympus Mons, Mars

For today’s mapping challenge, my theme is elevation. As a follow up to my earlier UFO/UAP maps, I wanted to do something otherworldly and decided to make a map featuring Olympus Mons, a giant extinct volcano on Mars. The volcano is bigger than any mountain on Earth. In fact, it is the largest known mountain in our solar system.

Approach

To make this map, I relied on a wonderful open source Digital Elevation Model (DEM) of the Martian surface that was derived from NASA’s Mars Orbiter Laser Altimeter (MOLA). This DEM provides planet-wide coverage and has a resolution of 200 meters per pixel, providing a for a detailed view of the red planet’s surface.  

After downloading and importing the Mars DEM into ArcGIS Pro, I converted my project to the Mars 2000 geographic coordinate system. I was pleased to see this supported by ArcGIS.  Once I had my DEM loaded and my geographic coordinate system locked in, I started creating a series of traditional and multi-directional hillshades, doing something slightly different with each one. I started staking them on top of each other and experimented with various color ramps and different blend modes until I settled on something that approximated what I imagine the surface of Mars to look like, based on photos I have seen, both from orbit and from rovers. I then zoomed in on Olympus Mons, the focus of today’s map.  

Once I had the location set, I decided to add a visual callout. I followed a great video tutorial on how to do this that was created by John Nelson, which you can find here. The callout focuses a viewer’s attention on the mountain and pushes the other terrain elements towards the background.

From there, I added map text, attribution for the MOLA data and signed my work. Overall, I really liked how these maps turned out.

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