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In article <2hqMf.4081$S25.2832@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Buck
Fusche wrote:
> These two facts add up to near complete uncertainty about
> the frequency of major impacts.
>
The geological record adds up to a high degree of certainty
about the frequency of major impacts. Minor impacts are less well
constrained however, because they leave smaller marks across smaller
regions.
That our understanding of the major components of the Solar
system is good enough to allow us to position devices to an accuracy of
a few kilometers on a different planet is a demonstrated fact. We're
not perfect, but we're not hopeless. What is needed for more confidence
is deeper vision (spotting smaller and/ or faster moving objects), and
we can make credible estimates of how many of them there are. And
astronomers are fully aware that they're making *estimates*.
--
Aidan Karley FGS
Aberdeen, Scotland,
Location: 57°10'11" N, 02°08'43" W (sub-tropical Aberdeen), 0.021233
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