About the data
How We Identify the Top Potentially Habitable Exoplanets
At BetterThanEarth.com, we aim to highlight the most promising known exoplanets that could — in theory — support liquid water and perhaps even life as we understand it. To do this fairly and accurately, we combine two of the most respected public sources in exoplanet science:
- NASA Exoplanet Archive --The official NASA repository for confirmed exoplanets (maintained by the California Institute of Technology). We use the latest confirmed physical parameters — such as planet radius, mass, density, equilibrium temperature, orbital distance, and stellar flux (how much starlight the planet receives) — directly from their Planetary Systems Composite Parameters table (PSCompPars). This gives us the most up-to-date, peer-reviewed measurements available.
- Habitable Worlds Catalog (HWC) -- Created and maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo (PHL @ UPR Arecibo). The HWC is one of the leading expert classifications of potentially habitable worlds. It divides candidates into conservative (more likely rocky planets in the strict habitable zone where liquid water can stably exist on the surface) and optimistic (broader habitable zone, including possible water worlds or planets with thicker atmospheres). We heavily reference their rankings, Earth Similarity Index (ESI) values, and habitability assessments.
Our Approach to Selecting Candidates
We pull the latest data from the NASA Exoplanet Archive and automatically evaluate planets using a weighted habitability score (0–100). Higher scores = better candidates for life as we know it.
Selection Criteria (in simple terms)
- Confirmed planets only — Only verified discoveries.
- Habitable Zone — The planet gets the right amount of starlight for liquid water to exist.
- Earth Similarity — Close in size, mass, and temperature to Earth.
- Rocky Size — Preference for Earth-sized or slightly larger rocky worlds.
- Stable Star — Prefers longer-lived, calmer stars (especially orange K-dwarfs, then Sun-like stars).
Scoring Breakdown (Weighted)
- Earth Similarity Index (ESI): 40 points
- Habitable Zone match: 35 points
- Planet Size (rocky preference): 15 points
- Stellar Type (star stability): 10 points
Important Notes
- All data is publicly available and credited to its original sources.
- No planet has been confirmed to be habitable — these are scientifically promising candidates only. However, we intend to keep the data as fresh as possible from multiple data sources.
- Rankings and assessments evolve quickly as new observations (especially from the James Webb Space Telescope) and updated catalogs become available. Our list reflects the best information as of early 2026.
- We are not affiliated with NASA or PHL @ UPR Arecibo; we are an independent enthusiast project synthesizing publicly available research for educational and inspirational purposes.
Data Sources & Credits
- NASA Exoplanet Archive: https://exoplanetarchive.ipac.caltech.edu
- Habitable Worlds Catalog (PHL @ UPR Arecibo): https://phl.upr.edu/hwc
- Additional context from peer-reviewed papers, JWST early results, and community discussions.
We believe transparency is essential when talking about the search for other Earths. Thank you for exploring these incredible worlds with us!