NASA Open Data (data.nasa.gov) publishes 36,378 open datasets for Global. Browse them live in Vizzie and turn any one into a map or chart.
NASA Open Data (data.nasa.gov) is the open-data portal for Global. It runs on CKAN, an open catalogue standard used by many national governments. You can browse it directly at data.nasa.gov. Reuse terms are set out in the portal's terms of service (Portal-specific terms page; licence is carried per dataset.).
NASA Open Data (data.nasa.gov) publishes one licence across its whole catalogue, so 29,498 datasets here are covered by it even though they carry no licence of their own. That is a stronger position than an undeclared catalogue, where nothing grants permission at all — but the portal's terms are what govern, so read them before you rely on the data. Vizzie resolves each dataset to the same licence and writes the attribution line for you when you export or publish.
81% undeclared, but NASA works are US federal public domain by default (17 USC §105). Safe to apply US-PD as the portal default. Attribute anyway.
No download, no GIS specialist. Opens in Vizzie.