The Habitable Worlds Catalog is a running list of exoplanets that meet habitability-motivated criteria (habitable-zone orbit, appropriate mass/radius bounds, stable host). Maintained by the Planetary Habitability Laboratory (PHL) at the University of Puerto Rico at Arecibo, it included roughly 70 entries out of more than 5,000 known exoplanets as of 2026.
Recent additions relevant to this wiki include gj-887-d (src-gj-887-d-habitability-2026-03) and k2-18b (though K2-18b’s interpretation as habitable is disputed — see src-k2-18b-technosignature-null-2026).
The catalog uses classical habitable-zone criteria. The 2026 interplanetary-habitable-zone framework (src-interplanetary-habitable-zone-2026) suggests several catalog entries — notably the trappist-1 planets — may be unsuitable for advanced civilizations even if they remain plausible biosignature targets.