The U.S. space agency NASA has announced that the number of confirmed exoplanets has surpassed 6,000 — a remarkable achievement accomplished in just three decades of exploring worlds beyond our Solar System. Just a few years ago, that number stood at 5,000, highlighting an accelerating pace of discovery and increasingly efficient detection methods for distant planets.
This latest milestone nearly coincides with the anniversary of the discovery of 51 Pegasi b — the first planet found orbiting a Sun-like star, detected in 1995. That gas giant marked the beginning of a new era in astronomy. Although the first exoplanet was technically found in 1992, it orbited a pulsar — a highly unusual type of star.
NASA’s astronomers currently maintain a global registry containing over 8,000 candidate exoplanets awaiting confirmation. While no planet is officially labeled as the “6,000th” entry, the total is constantly updated as new worlds are verified. One of the latest additions is KMT-2023-BLG-1896L b, a Neptune-like planet with a mass roughly 16.35 times that of Earth.
The now-retired Kepler space telescope was responsible for over 2,600 discoveries, while its successor, TESS, has detected more than 690 planets so far. These technologies enable continuous monitoring of the sky and the analysis of planetary transits — when a planet passes in front of its host star — which helps identify planets of various sizes and compositions.
Neptune-like planets dominate NASA’s catalog, with more than 2,000 of them featuring thick hydrogen-helium atmospheres and rocky or metallic cores. In addition, there are nearly 2,000 gas giants and over 1,700 super-Earths — planets larger than Earth but less massive than Uranus or Neptune.
Currently, the list includes 700 “terrestrial planets,” or rocky worlds similar in composition to Earth. The rest are classified as “unknown” types, pending further study. The diversity of these discoveries provides scientists with vital clues about where and how planets form, and under what conditions.
According to Dawn Gelino, head of NASA’s Exoplanet Exploration Program at the Jet Propulsion Laboratory in Southern California, every piece of data helps address one of humanity’s biggest questions: Are we alone in the universe? Although a true Earth twin hasn’t been found yet, the search continues — and the cosmos, vast and full of mysteries, still holds countless undiscovered worlds.