Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Q-type asteroids: Possibility of non-fresh weathered surfaces   Itokawa particles, which are the recovered samples from the S-complex
asteroid 25143 Itokawa by the Hayabusa spacecraft, demonstrate that S-complex
asteroids are parent bodies of ordinary chondrite meteorites. Furthermore, they
clarify that the space weathering age of the Itokawa surface is of the order of
several thousand years. Traditionally, Q-type asteroids have been considered
fresh-surfaced. However, as the space weathering timescale is approximately
three orders of magnitude lesser than the conventionally considered age, the
previously proposed formation mechanisms of Q-type asteroids cannot
sufficiently explain the surface refreshening. In this study, we propose a new
hypothesis on the surface state of Q-type asteroids: Q-type asteroids have a
non-fresh weathered surface with a paucity of fine particles. For verifying
this hypothesis, laboratory experiments on the space weathering of ordinary
chondrites are performed. Based on the results of these experiments, we found
that large (more than 100 {\mu}m) ordinary chondritic particles with space
weathering exhibit spectra consistent with Q-type asteroids.

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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: cond-mat
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The categories of this paper are: physics