We present a reanalysis of HST images of five asteroids with known companions (45 Eugenia, 87 Sylvia, 93 Minerva, 107 Camilla, 121 Hermione). It is remarkable that all of these companion bodies are much redder in the visible region than their primary bodies. Storrs et al. (2009, BAAS vol. 41, no. 4, p 189) attributed this to space weathering, however, all of these bodies belong to dark C- or X-type groups. Current modeling of space weathering effects are limited to bright asteroids (e.g. Cloutis et al., Icarus 252, pp. 39-82, 2015) and show little change on the scale reported here. We suggest that the interaction of dark, possibly organic-rich surfaces with the solar wind produces reddening on a much greater scale than is observed in bright, silica-rich surfaces, and that this effect is easily reset by collisions. Thus, while both the parent and companion object accumulate the effects, the parent is much more likely to be "reset" by small collisions than the companion, due to the differences in their cross-sections.
American Astronomical Society Meeting Abstracts #227
- Pub Date:
- January 2016