Webb Telescope Reveals Dynamic Asteroid Rings

Astronomers using the James Webb Space Telescope (JWST) have discovered dynamic changes in the rings of the small solar system body Chariklo. This Centaur asteroid, approximately 155 miles (250 kilometers) wide, orbits between Saturn and Uranus and was found to possess two thick rings. Initial observations in 2013 revealed these rings, but recent JWST data from October 2022 has provided new insights.

By employing a stellar occultation technique, scientists observed a decrease in starlight as Chariklo passed in front of a star. Comparing these new observations with data from the past decade revealed a significant difference: the inner ring of Chariklo has become more opaque, while the outer ring has become less opaque. This suggests the rings are undergoing complex physical processes previously not expected for such small celestial bodies.

These findings challenge existing theories about the stability and evolution of rings around smaller objects in the solar system. The research, which utilized precise orbital data from the European Space Agency's Gaia mission, indicates a need to re-evaluate how these ring systems form, evolve, and maintain their stability. The ability to detect these changes offers a new perspective on the dynamics of Chariklo's rings and potentially others in the solar system.

The precise nature of these changes and their underlying causes are currently unknown. The JWST's ability to resolve Chariklo's rings in unprecedented detail, despite not being able to image the asteroid directly, is a significant achievement. This research was published in the journal Science Advances.