A new planet-hunting instrument at W. M. Keck Observatory has achieved "first light," capturing its first data from the sky and marking an exciting chapter in the search for Earth-sized planets around other stars, which are extraordinarily difficult to detect due to their small size. Operating on the Keck I Telescope on Hawaiʻi Island's Maunakea, the Keck Planet Finder (KPF) is the world's most advanced high-resolution spectrometer for visible wavelengths.