AI-ASSISTED · EDITOR-REVIEWED
Theme brief
Light and dark can be subject, style or both: night lights, light pollution, hillshade, solar exposure or chiaroscuro cartography. Preserve tonal separation and avoid crushing quiet data into a decorative black background.
Official prompt“Play with visual effects. What can you map with just light and shadows?”
30DayMapChallenge 2026
WAYS IN
Four map ideas
- 01
Map the edge of urban light around a dark-sky site.
- 02
Use a single hillshade to tell a terrain story without boundaries.
- 03
Compare seasonal darkness with population and transport.
- 04
Create a black-and-white map where light alone reveals the street network.
IN THE DIRECTORY
Recommended tools
QGIS
Excellent for multidirectional hillshade, blend modes and tonal control.
Open source · View detailsGoogle Earth Engine
Processes night-light and terrain rasters across time and large areas.
Freemium · View detailsBlenderGIS
Supports dramatic terrain lighting and rendered shadows.
Open source · View detailsNASA Worldview
Makes daily and long-term Earth imagery easy to inspect.
Free · View detailsSTART WITH A CLEAR LICENSE
Data sources
Night-time light products at daily, monthly and annual intervals.
Open NASA data · attribution requested Copernicus DEMGlobal elevation models at 30 m and 90 m spacing.
Free use under Copernicus terms VIIRS night-time lightsAnnual and monthly composites from the Earth Observation Group.
Free for research and education · check product termsLicenses are a planning aid, not legal advice. Check the source record and version you actually download; terms can vary within a catalog.
BEFORE YOU EXPORT
Cartography check
Check the map in a bright room and on a phone. Subtle dark tones that work on your monitor may merge elsewhere.
COMMUNITY MAPS
Selected work
First participate officially by posting publicly with #30DayMapChallenge. You can then suggest that original post for our independent MapTools picks. We link to the source, credit every author and use images only with permission.
Suggest for MapTools picks