Overview
- A peer-reviewed study in Science reports that Hubble directly imaged two transient dust clouds in Fomalhaut’s debris ring produced by separate planetesimal collisions.
- The long-debated source dubbed Fomalhaut b is reclassified as a dissipating debris cloud now labeled cs1, while a new bright source, cs2, marks a recent impact supported by four independent analyses.
- Researchers say these are the first direct observations of colliding planetesimals outside the solar system.
- The dust clouds indicate impactors on the order of tens of kilometers across, and two events in roughly 20 years challenge models that expect such collisions only about once every 100,000 years.
- With Hubble’s 2024 gyro failure curbing steady follow-up, teams have approved JWST observations to track cs2’s brightness, color and expansion to probe composition and sharpen methods for distinguishing dust clouds from planets.