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Updated: Jul 22, 2026

Laboratory Drop Towers for the Experimental Simulation of Dust-aggregate Collisions in the Early Solar System
Published on: June 5, 2014
Dark matter in the outer solar system
T Owen1, D Cruikshank, C de Bergh
1University of Hawaii Institute for Astronomy, Honolulu 96822, USA.
Abstract:
There are now a large number of small bodies in the outer solar system that are known to be covered with dark material. Attempts to identify that material have been thwarted by the absence of discrete absorption features in the reflection spectra of these planetesimals. An absorption at 2.2 micrometers that appeared to be present in several objects has not been confirmed by new observations. Three absorptions in the spectrum of the unusually red planetesimal 5145 Pholus are well-established, but their identity remains a mystery.
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