NASA’s Webb Finds Clues to Ancient, Distant Origin of Comet 3I/ATLAS

Comparison of three telescope images side by side. They are roughly spherical but pixelated, with more intense color saturation in the center. From left to right: smallest sphere is blue and labeled H2O, orange is larger and labeled CO2, and red is largest and labeled CO. A scale bar at the lower left is labeled 1300 km/1 arcsecond and is about one fourth of each of the three images. A compass at the lower right shows north pointing up to 12 o’clock, east pointing left to 9 o’clock, and a fainter arrow labeled to Sun pointing down to 8 o’clock.

As interstellar comet 3I/ATLAS began moving away from the Sun in December 2025, astronomers took the opportunity to turn NASA’s powerful James Webb Space Telescope in its direction and capture detailed measurements of its chemical components. The comet was freshly warmed from its closest pass by the Sun, and its ancient ice had been converted … Continue reading NASA’s Webb Finds Clues to Ancient, Distant Origin of Comet 3I/ATLAS