JWST detected an icy world beyond Jupiter transforming into a comet
JWST detected carbon dioxide gas around the active Centaur 450P/LONEOS while finding no detectable water-vapor or carbon-monoxide emission, pointing to CO₂ as an important driver of its distant activity. A close encounter with Saturn in 1992 shifted 450P onto a warmer orbit, and thermal modeling favors carbon dioxide released as buried amorphous water ice crystallizes. The object may offer astronomers a rare view of a Centaur undergoing the physical changes that can eventually turn members of this population into Jupiter-family comets. More than 3 billion miles from Earth, a small frozen world is showing what may happen when an ancient object from the solar system’s deep freeze begins a journey toward becoming a comet. The object, 450P/LONEOS, belongs to the Centaurs, icy bodies whose unstable orbits generally carry them among the giant planets. Observations with NASA’s James Webb Space Telescope and the Gemini North telescope reveal a growing cloud of dust, carbon dioxide gas and water-rich icy grains around its nucleus. The UCF-led team, headed by planetary scientist Charles Schambeau, argues that 450P offers an …









