Relief normal maps (tools/build-relief-normals.py): derived slopes, not imagery. No endorsement implied.

Mercury: Mercury MESSENGER Global DEM 665m (64 ppd) v2, USGS Astrogeology (Becker et al. 2016). NASA/JHUAPL/Carnegie Institution of Washington (MESSENGER); USGS Astrogeology Science Center (Becker, K. J., et al. 2016, LPSC 47, 2959). Public domain (USGS Astrogeology product of NASA mission data); credit requested, no endorsement implied. https://astrogeology.usgs.gov/search/map/mercury_messenger_global_dem_665m
Mars: MGS MOLA Mission Experiment Gridded Data Record, topography, 16 pixels per degree (MEGT90N000EB, product version 2.0). NASA/JPL/GSFC (MGS MOLA Science Team); PDS Geosciences Node. NASA mission data, public domain in the United States (PDS archive); credit requested, no endorsement implied. https://pds-geosciences.wustl.edu/missions/mgs/megdr.html