Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamical Origin and Terrestrial Impact Flux of Large Near-Earth
  Asteroids   Dynamical models of the asteroid delivery from the main belt suggest that the
current impact flux of diameter D>10 km asteroids on the Earth is 0.5-1 per
Gyr. Studies of the Near-Earth Asteroid (NEA) population find a much higher
flux, with ~7 D>10-km asteroid impacts per Gyr. Here we show that this problem
is rooted in the application of impact probability of small NEAs (1.5 per Gyr
per object), whose population is well characterized, to large NEAs. In reality,
large NEAs evolve from the main belt by different escape routes, have a
different orbital distribution, and lower impact probabilities (0.8+/-0.3 per
Gyr per object) than small NEAs. In addition, we find that the current
population of two D>10 km NEAs (Ganymed and Eros) is a slight fluctuation over
the long term average of 1.1+/-0.5 D>10 km NEAs in a steady state. These
results have important implications for our understanding of the occurrence of
the K/T-scale impacts on the terrestrial worlds.

8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol