2006/03/24 by Henry H. Hsieh, David Jewitt · 5 citations
Physics and Astronomy · #Astro and Planetary Science #Stellar, planetary, and galactic studies #Planetary Science and Exploration
paper · doi:10.1126/science.1125150
openalex publication_date 2006/03/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Comets are icy bodies that sublimate and become active when close to the Sun. They are believed to originate in two cold reservoirs beyond the orbit of Neptune: the Kuiper Belt (equilibrium temperatures of approximately 40 kelvin) and the Oort Cloud (approximately 10 kelvin). We present optical data showing the existence of a population of comets originating in a third reservoir: the main asteroid belt. The main-belt comets are unlike the Kuiper Belt and Oort Cloud comets in that they likely formed where they currently reside and may be collisionally activated. The existence of the main-belt comets lends new support to the idea that main-belt objects could be a major source of terrestrial water.