After nine years of operation, NASA's Kepler spacecraft will be retired, but not without making an indelible imprint on humankind's understanding of the universe. Perhaps its greatest legacy is the knowledge that planets outnumber stars in the galaxy. With over 2,500 planet discoveries and another 2,000 awaiting confirmation, Kepler revealed a staggering diversity of worlds turning sci-fi fantasy into scientific reality. It also changed our collective perspective regarding the feasibility of finding evidence of life beyond Earth and catalysed efforts across the globe to reach that goal.