[Updated 5 June 2019]

Writing this as it’s still fresh in mind (looking at a lot of drafts sitting in my notebook) as well as for the next print if any. I can and will update this, but for now, it’s publishable in my standard.

I have just obtained an opportunity to do outreach. It’s a very interesting event, and as I previously have obtained a 3-D print of Gale Crater, I was very interested to create a print of my area of research (still Mars, but more to the south)

The print in question. As blurry as it can get  Anyone can guess what this is?

Other than a good prop to show to students and children, 3D printed products is a good way to show information to people with sight disabilities. For anyone interested in printing their own crater/ planet/ asteroid, let me link sources and share how to (so that I don’t need to learn again in the future!). To be able to 3D-print things, you definitely have to have access to a 3D printer. For this, my current university has its own makerspace. As my lab is in the middle of nowhere (more like antah berantah, really) and the university 3D printer works a first-come-first-serve basis, it’s not ideal. Fortunately, my lab has its own 3D printer and my colleague (thank you, Craig) had agreed to help me with the process, very thankful for this.

Note: You need to have:

• access to a 3D printer
• enough 3D-printer filament (PLA and ABS are commonly used)
• computer/ notebook

Printing available STL

This is the easiest way. Other than official sources, a lot of people has successfully printed their own planetary surface and very kindly uploaded their files on the world wide web.

• NASA 3D resources. Including lunar landing sites, martian rover sites, asteroids, and spacecraft, with an ever-growing collection
• Neurothing@Thingiverse. An avid planetary 3D printing enthusiast (has also worked officially to produce 3D models). Including the whole Mars globe, asteroids, Europa, craters and landing site, tardigrades!!
• Earth. Wired version by Ferjerez@Thingiverse.
• Solar system. One that can work as desk decoration (because it’s scientific and pretty) by sebastianliebhart@Thingiverse.
• Constellations. mfritz@Thingiverse
• Quadrant. Mirkoengineer@Thingiverse.
• SpaceX Falcon9. Enderfusion@Thingiverse (warning: very large!!)
• Sojourner. Nm081301@Thingiverse
• NASA 34M antenna. Chzed@Thingiverse.
• NASA logo because why not. AeroScience@Thingiverse.
• 3D Asteroid Catalogue (Need to convert filetype but it has most asteroids)
• etc. (still scouring through the internet)

Creating STL files from DTM

First, the DTM… DTM or Digital Terrain Model (on Earth we also have DEM, Digital Elevation Model, and DSM, Digital Surface Model. The good thing about other celestial bodies is that they don’t have trees, water, buildings, all three terms work).

You can download them officially on their websites. My DTM knowledge is not solar-system-wide, so maybe missing a lot of them. Generally, you can scrounge through the USGS website.

• Mars. Global MOLA (463m/pixel). Global MOLA blended with HRSC (200m/pixel, a better result for large-scale printing), HRSC (50-200m/pixel, download the DT4 or DA4 files). CTX (12m/pixel. A lot has been made, but a lot is unpublished. Syrtis Crater (20m/pixel), McLaughin (20m/pixel)). HiRISE (max. 75 cm/pixel). Gale Crater merged from HIRISE-CTX-HRSC-MOLA (1m/pixel). Phobos HRSC Global (100m/pixel)
• Moon. LRO LOLA (118m/pixel). Merge of LRO LOLA and Kaguya (59m/pixel, —60^o-60^o,better result for large-scale printing). South pole LROC NAC (4m/pixel)
• Mercury Messenger Global (665m/pixel)
• Venus Magellan (4641m/pixel)
• Pluto GlobalNew Horizon. Charon Global New Horizon (300m/pixel)
• Ceres Hamo Dawn (137m/pixel)

For HiRISE (which is the camera with the higher resolution on Mars, until 25 cm/pixel! (my anecdote is that if you sunbathe on Mars, you’ll be pictured easily in more than 6 pixels), there is a Blender plugin which can easily import your downloaded files.

For georeferenced earth DEM in tiff, there is another Blender plugin.

As I don’t use HiRISE data for this print and I can’t manage to work the Blender Earth plugin out, I end up using the Heightmap to STL, a Javascript by mfussi@Thingiverse. I export my GeoTiff to png before running the software. There is an excellent tutorial here.

[Update: you can download HiRISE 3D-ready files from Areo Browser or choosing your area of interest at Mars Trek then export]

Other methods: result obtained from Googling

• Earth Surface. Using Google Earth and Photoshop (Roy Smith@MatterHackers)
• There is also phstl@Github to turn GeoTiff to STL using a Unix-based command line.

Other Alternatives

Afraid not! Even though you don’t have any access to a 3D printer, you can actually do a similar thing with other methods. One method is to use a laser cutter (another machine, really). You can make this laser-cutter printed surface in two ways. One is to ensure that you have a grayscale DTM file with darker colours representing lower altitude (generally it’s like this, but just in case), then follow this tutorial to change a photo to laser-engraving. The thicker your surface is, I believe, the better your result is (I’ve done a photo to laser-engraving, maybe next post). Another alternative with a laser cutter is to create a contour map (the more contour, the more detail and the thicker the model will be), then laser cutting each contour in a layer of plywood, then glue them together. An example here for a laser-cut bathymetric map. If all else fails, you can hand-cut them yourself! (I’ve seen someone’s turning their thesis to lunar craters, but can’t seem to find it. Next time, maybe. Update: Found it here)

Laser cut-bathymetric map (LoganB23@instructables)

(To do: Sources for other STL files, such as terrain, hurricane, or earthquake data. More examples and better sourcing)