Dust in the Solar System: Properties and Origins

How Many Hydrated NEOs Are There?

“…This can be seen by looking at the interplanetary dust particle (IDP) collection. IDPs <100 μm in size and collected at altitude have characteristics that differ from the larger particles (and meteorites) that reach the ground (Messenger et al, ). One of the three major compositional‐textural groups of IDPs (the chondritic, smooth, and compact particles: CS) are composed mostly of hydrated minerals (Schramm et al, ).…”

“…The CS IDPs are broadly similar to the CM and CI chondrites and are thought to have asteroidal origins, but it is not clear if they are from literally the same parent bodies as the larger CM and CI meteorites. One of the other major IDP groups, the chondritic‐porous (CP) group, is seen to be extremely fragile and often do not survive collection or sample preparation intact (Messenger et al, ).…”

The physical and compositional properties of dust: what do we really know?

“…They are also going to be something of a compromised fit to real dust SED observational data. Also, our current knowledge of the 'real' nature of the large amorphous silicate grains in the ISM is far from complete but should perhaps be better guided by the analysis of the pre-solar silicate grains extracted from primitive meteorites [21]. [22,23], indicate that the dust elemental composition is dominated by C, O, Si, Mg and Fe with minor amounts of Na, Al, Ca and Ni and traces of K, Ti, Cr, Mn, and Co.…”

“…While interstellar elemental depletion studies are able to indicate the stoichiometric composition of the condensed solid phase in the ISM they reveal nothing of the , their composition appears to be Mg-rich and there is little direct evidence for Fe oxides, which leaves sulphides and metal as the best candidates. A mix of Fe metal and sulphide could temptingly be identified with the thorny problem of the origin of the GEMS (Glass with Embedded Metal and Sulphides) but this component of the interplanetary dust particles (IDPs) has now been demonstrated to be of solar nebula origin [21]. The problem of interstellar Fe is discussed again within the framework of interstellar silicates in § 9.…”