Characterization of preserved primitive fine-grained material from the Jupiter family comet 81P/Wild 2 - A new link between comets and CP-IDPs

- We report the presence of a primitive condensate in the comet Wild 2.
- We show comet Wild 2 is linked with CP-IDPs.
- We show that primitive fine-grained material could meet chondrule-like objects in outer Solar System.

We report the presence of preserved primitive fine-grained material containing an enstatite whisker with the crystallographic characteristics of a primary condensate in a sample of the Jupiter-family comet Wild 2, returned to earth by NASAʼs Stardust mission. The preserved primitive material is composed of silica-rich amorphous material embedded with iron sulfides and silicates. It is in close association with a type II chondrule-like object in the track C2052,2,74 (Ogliore et al., 2012). The close association of a chondrule and a primary condensate shows they must have formed in different environments and probably met in the comet-forming region. The first observation of an enstatite whisker with properties indicating primary condensation in a comet is a new link between comets and Chondritic Porous IDPs (CP-IDPs).