Olivine-rich asteroids in the near-Earth space

M. Popescu, D. Perna, M. A. Barucci, S. Fornasier, A. Doressoundiram, C. Lantz, F. Merlin, I. N. Belskaya, M. Fulchignoni
(Submitted on 12 Mar 2018)

In the framework of a 30-night spectroscopic survey of small near-Earth asteroids (NEAs) we present new results regarding the identification of olivine-rich objects. The following NEAs were classified as A-type using visible spectra obtained with 3.6 m NTT telescope: (293726) 2007 RQ17, (444584) 2006 UK, 2012 NP, 2014 YS34, 2015 HB117, 2015 LH, 2015 TB179, 2015 TW144. We determined a relative abundance of $5.4\% $ (8 out of 147 observed targets) A-types at hundred meter size range of NEAs population. The ratio is at least five times larger compared with the previously known A-types, which represent less than $\sim1\%$ of NEAs taxonomically classified. By taking into account that part of our targets may not be confirmed as olivine-rich asteroids by their near-infrared spectra, or they can have a nebular origin, our result provides an upper-limit estimation of mantle fragments at size ranges bellow 300m. Our findings are compared with the “battered-to-bits” scenario, claiming that at small sizes the olivine-rich objects should be more abundant when compared with basaltic and iron ones.

Comments:    10 pages, 4 figures, accepted for publication
Subjects:    Earth and Planetary Astrophysics (astro-ph.EP)
Cite as:    arXiv:1803.04486 [astro-ph.EP] (or arXiv:1803.04486v1 [astro-ph.EP] for this version)
Submission history
From: Marcel Popescu
[v1] Mon, 12 Mar 2018 19:39:51 GMT (1416kb,D)
https://arxiv.org/abs/1803.04486