Out of 6,286 confirmed exoplanets, only 38 are roughly Earth-sized and sit in a temperature range where liquid water could exist. Two of them orbit Proxima Centauri — our nearest stellar neighbor, just 4.2 light-years away.
That ratio — 38 out of 6,286, or 0.6% — sounds tiny, but it's a revolution. Before 2014, the entire confirmed exoplanet catalog held only 909 worlds. Since then, missions like Kepler, TESS, and ground-based radial velocity surveys have added 5,376 more, turning exoplanet science from a novelty into a census. The chart below shows how that census exploded.
The spike in 2016 is unmistakable: 1,496 planets confirmed in a single year, nearly all from a massive Kepler data release. That one batch added more worlds than the entire first two decades of exoplanet discovery combined (1992–2012 produced just 614 confirmations). The pace has stayed elevated since, with 200+ planets confirmed annually through 2026.
Transit Dominates — and That Shapes What We Find
How we look determines what we see. The transit method — watching for a star's brightness to dip as a planet crosses in front — accounts for 74% of all discoveries (4,647 planets). Radial velocity, the runner-up, captures 19%. Every other technique combined makes up just 7%.
This matters because transit detection is biased toward large planets on short orbits. Finding small, temperate worlds — the ones most like Earth — requires longer observation baselines and more precise instruments. That makes the 38 habitable-zone candidates all the more remarkable: they're the hardest type of planet to detect, yet we're finding them anyway.
The size distribution tells that story clearly. Most confirmed exoplanets cluster above 1.5 Earth radii — the mini-Neptunes and gas giants that transit surveys detect most easily. The Earth-sized bin is thinner, and within it, only a sliver falls in the right temperature window.
The Nearest Habitable Worlds
Among those 38, the proximity of several is striking. Proxima Centauri b (1.02 Earth radii, 218 K equilibrium temperature) and Proxima Cen d (0.69 Earth radii, 282 K) sit at just 1.3 parsecs. Ross 128 b is 3.4 parsecs out. Teegarden's Star hosts two candidates at 3.8 parsecs. TRAPPIST-1 d and e, at 12.4 parsecs, are already targets for James Webb Space Telescope atmospheric characterization.
These aren't abstractions. JWST is actively collecting spectra of TRAPPIST-1 e's atmosphere right now, searching for water vapor, CO₂, and potential biosignatures. Gliese 12 b (0.93 Earth radii, 315 K, 12.2 parsecs) was flagged in 2024 as one of the best candidates for atmospheric follow-up. Within a decade, we may know whether any of these worlds have atmospheres at all — the first step toward answering whether they could support life.
What Comes Next
The catalog will keep growing. ESA's PLATO mission, launching in 2026, is designed specifically to find Earth-sized planets in habitable zones around Sun-like stars — exactly the population that current surveys struggle to detect. If the current 0.6% rate holds or rises with better instruments, the question shifts from whether Earth-like worlds exist nearby to how many are close enough to study in detail. The 38 we know about today may be just the beginning.