Kepler Space Telescope (2009–2018)

Kepler Space Telescope revolutionized our understanding of exoplanets by surveying 150,000 stars over four years, detecting minuscule brightness dips from transiting planets. Its mission confirmed over 2,600 exoplanets, proving that planets outnumber stars in the Milky Way; a finding that reshaped the search for habitable worlds. This achievement outperforms #2 Hubble's exoplanet contributions in sheer discovery count, as Kepler identified 70% more confirmed planets than any previous observatory.