NASA’s newly launched PUNCH mission is already delivering a vivid glimpse into the solar system, capturing its first rainbow-hued images as it continues instrument calibration and commissioning. The Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission, consisting of four small satellites, is designed to study the outer atmosphere of the Sun—known as the corona—and how it evolves into the solar wind that permeates the solar system.
On April 18, 2025, the WFI-2 instrument (which captured its first light on April 14) took images through all three of its polarizers in succession for the first time to create this view. The image is colorized to show the polarization (or angle) of the zodiacal light, a faint glow from dust orbiting the Sun. Hue indicates direction, and saturation indicates degree of polarization. For example, a pastel green feature would be slightly polarized in the horizontal direction, while a deep blue feature would be strongly polarized in a diagonal direction. The Sun’s location is marked with a star symbol. Other stars in the sky appear white because they are mostly unpolarized compared to the 7% polarization of the zodiacal light. The compact Pleiades star cluster appears just above center, and the V-shaped Hyades star cluster appears to the upper left of the Pleiades.
Credit: NASA/SwRI
In a groundbreaking effort, PUNCH is the first mission tailored to measure the solar corona and solar wind in three dimensions using polarization—a property of light that reveals how it is scattered by particles. By encoding this polarization in color, PUNCH produces images with a rainbow palette that gives scientists a new window into the movement and structure of the solar wind.
Among the early achievements are the first images from two of PUNCH’s instruments, marking an important milestone in the mission. The four-satellite fleet includes one Narrow Field Imager (NFI) and three Wide Field Imagers (WFIs). The NFI functions as a coronagraph, blocking the Sun’s bright light to observe the faint details of the corona. Meanwhile, the WFIs peer into the outermost reaches of the corona and the solar wind itself.
The mission’s eventual science data will integrate views from all four spacecraft, filtering out background noise and camera artifacts to provide a seamless, high-resolution look at solar wind dynamics. These initial images confirm the instruments are operational, properly focused, and ready to capture the high-quality observations needed for mission success.
As the commissioning phase progresses, scientists will continue fine-tuning the instruments to unlock even more detail about the Sun’s complex outer layers and the ever-flowing solar wind. Among the early highlights is a stunning rainbow image of the zodiacal light—a glow produced by sunlight scattering off interplanetary dust—offering a colorful preview of the scientific discoveries to come.
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