Saturn Encounter May Have Triggered Centaur’s Transformation Into Comet
- An ancient icy object located more than 3 billion miles from Earth is slowly awakening and showing signs of transforming into a comet, according to research published in...
- Researchers led by University of Central Florida planetary scientist and associate professor Charles Schambeau believe that Centaur 450P/LONEOS began activating after a close gravitational encounter with Saturn in...
- Observations from the James Webb Space Telescope and the Gemini North telescope in Hawaii enabled scientists to detect carbon dioxide gas, icy dust, and signs of recent thermal...
An ancient icy object located more than 3 billion miles from Earth is slowly awakening and showing signs of transforming into a comet, according to research published in the Planetary Science Journal. The frozen body, known as Centaur 450P/LONEOS, has begun releasing gas and dust as it drifts inward through the solar system, displaying behavior typically associated with comets rather than centaurs, which usually orbit between Jupiter and Neptune.
Gravity Assist Alters Centaur Orbit
Researchers led by University of Central Florida planetary scientist and associate professor Charles Schambeau believe that Centaur 450P/LONEOS began activating after a close gravitational encounter with Saturn in 1992 significantly altered its orbit, according to the study. The interaction shifted the object inward from a more distant trajectory, bringing its perihelion—the point in its orbit closest to the Sun—closer to Jupiter. As the centaur moved closer to the Sun, scientists observed the gradual formation of a faint coma, which is a cloud of gas and dust surrounding the nucleus. Continued monitoring between 2019 and 2024 revealed that the coma became increasingly visible as the object’s distance from the Sun decreased. That increased solar heating can warm the surface and subsurface layers of the nucleus, according to Schambeau, allowing volatile ices or trapped gases to escape and drag dust away from the surface.
Carbon Dioxide Drives Cometary Activity
Observations from the James Webb Space Telescope and the Gemini North telescope in Hawaii enabled scientists to detect carbon dioxide gas, icy dust, and signs of recent thermal activity surrounding 450P/LONEOS. The detection of carbon dioxide was particularly significant because the nucleus is too cold at that distance from the Sun for normal water-ice sublimation to serve as the main activity source, according to researchers. The observations revealed strong evidence of carbon dioxide emission alongside icy dust grains in the coma, including possible signs of crystalline water ice. The research team found no signs of water vapor or carbon monoxide. The findings suggest that the material in the coma has experienced heating or physical processing rather than remaining completely unchanged since its formation, according to the study’s findings.
