Map Pluto's ices at 7 kilometers per pixel. From a single flyby nine years ago.
New surface composition and temperature maps of Pluto (arXiv:2603.21860): five close-approach observations from New Horizons' RALPH/LEISA near-infrared spectrometer, co-registered into a unified map. Joint retrieval of surface temperature, ice abundances (methane-rich, nitrogen-rich, water ice), grain sizes, and Titan tholin coverage using a Hapke-based mixing model.
The technical challenges: scan-to-scan artifacts from a moving spacecraft, variable spatial resolution across the flyby, bad pixels, and spectral inconsistencies. Each observation captured a different slice of Pluto's surface at a different resolution and viewing angle. The co-registration aligns them into a single coherent map — but the stitching must account for the changing illumination, viewing geometry, and instrumental effects.
The result: detailed regional maps showing Pluto's ice geography. Nitrogen ice dominates the smooth plains of Sputnik Planitia (the heart-shaped basin). Methane ice covers the highlands. Water ice appears at low latitudes where nitrogen and methane have sublimated away. Tholin (complex organic compounds produced by UV irradiation of methane and nitrogen) covers the equatorial dark regions.
The structural insight: one spacecraft, one flyby, nine years of analysis. The data was collected in hours and has been yielding science for nearly a decade. Each new analysis technique applied to the same data reveals something the previous technique missed. The observation is fixed; the information extracted from it keeps growing. The data is richer than any single analysis can exhaust — because the physics (scattering, mixing, temperature) encodes more information in the spectrum than any one model extracts.