Asteroid (354) Eleonora: Plucking an odd duck

Mineralogically diagnostic spectral parameters extracted from this new data are most consistent with a surface assemblage of fine-grained intimately mixed olivine (∼60-70%, ∼Fo61-71) and low nickel (<∼7-8% Ni) NiFe metal. The Fo estimate is consistent with previous estimates (Fo66±5) by Sanchez et al. (Sanchez, J.A., Reddy, V., Kelley, M.S., Cloutis, E.A., Bottke, W.F., Nesvorný, D., Lucas, M.P., Hardersen, P.S., Gaffey, M.J., Abell, P.A., Le Corre, L. [2014]. Icarus 228, 288-300), but not with the estimate (∼Fo90) of Sunshine et al. (Sunshine, J.M., Bus, S.J., Corrigan, C.M., McCoy, T.J., Burbine, T.H. [2007]. Meteorit. Planet. Sci. 42, 155-170). The surface assemblage appears to contain a small component (∼8-10%) of igneous pyroxene (weakly constrained at ∼Fs50Wo10). The parent lithology of the surface regolith may be similar to a pallasite assemblage, although none of the three known types of pallasites are good mineralogical matches.