New Horizons at Pluto (NASA, 2015)

New Horizons transformed Pluto from a blurry dot into a dynamic world, revealing nitrogen glaciers, water-ice mountains as tall as the Rockies, and a layered atmosphere during its 2015 flyby—data that upended the expectation that small, cold bodies are geologically dead. The spacecraft traveled 5 billion km in 9 years, and its visit to Pluto outperformed the distant images from the Hubble Space Telescope by more than 10,000 times in resolution. In 2019, it went further, visiting Arrokoth 6.5 billion km from the Sun, the most distant object ever encountered. New Horizons’ findings have redefined our understanding of the outer solar system’s geology and continue to inspire missions like NASA’s proposed Uranus Orbiter and Probe.