NASA's SPHEREx Telescope Observes Comet 3I/ATLAS's Dramatic Flare-Up as It Exits Solar System
NASA's SPHEREx space telescope has captured remarkable infrared observations of the interstellar comet 3I/ATLAS as it exits the solar system. In December 2025, the telescope recorded the comet releasing a significant surge of gas, dust, and complex molecules, providing scientists with an unprecedented chemical view of material formed around another star. This event occurred two months after the comet's closest approach to the sun, during which it unexpectedly brightened and developed a glowing coma rich in water vapor, carbon dioxide, and organic compounds. The comet, discovered in July 2025, is only the third confirmed interstellar object to pass through our solar system, following 1I/'Oumuamua and 2I/Borisov. Unlike its predecessors, 3I/ATLAS exhibited an extended chemical display, which SPHEREx was uniquely equipped to observe.