Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How Many Ore-Bearing Asteroids?   A simple formalism is presented to assess how many asteroids contain ore,
i.e. commercially profitable material, and not merely a high concentration of a
resource. I apply this formalism to two resource cases: platinum group metals
(PGMs) and water. Assuming for now that only Ni-Fe asteroids are of interest
for PGMs, then 1% of NEOs are rich in PGMs. The dearth of ultra-low delta-v
(<4.5 km s-1) NEOs larger than 100 m diameter reduces the ore-bearing fraction
to only ~1 in 2000 NEOs. As 100 m diameter NEOs are needed to have a value >=
US$1 B and the population of near-Earth objects (NEOs) larger than 100 m
diameter is ~20,000 (Mainzer et al. 2011) the total population of PGM
ore-bearing NEOs is roughly 10. I stress that this is a conservative and highly
uncertain value. For example, an order of magnitude increase in PGM ore-bearing
NEOs occurs if delta-v can as large as 5.7 km s-1. Water ore for utilization in
space is likely to be found in ~1/1100 NEOs. NEOs as small as 18 m diameter can
be water-ore-bodies because of the high richness of water (~20%) expected in
~25% of carbonaceous asteroids, bringing the number of water-ore-bearing NEOs
to ~9000 out of the 10 million NEOs of this size. These small NEOs are,
however, hard to find with present surveys. There will be ~18 water-ore-bearing
NEOs >100 m diameter. These estimates are at present highly imprecise and
sensitive to small changes, especially in the maximum delta-v allowed.
Nonetheless the low values found here mean that much improved determinations of
each of the terms of the formalism are urgently needed. If better estimates
still find small numbers of ore-bearing NEOs then thorough surveys for NEA
discovery and, especially, characterization are needed. Strategies for the two
classes are likely to be different.

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The categories of this paper are: plasm-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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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: comp-gas
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The categories of this paper are: stat
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: econ