Gavin Whittaker wrote:
In uk.sci.astronomy Gareth Slee writted:
: Million to One chance of a collision apparently.
: http://news.bbc.co.uk/1/hi/uk/3200019.stm

from which:

"The chances of a catastrophe are likely to become even slimmer once more
measurements of the asteroid's orbit have been made."

If this is true, shouldn't astronomers increase the number of
measurements? If we look REALLY hard, we might be able to push it into
Jupiter.

A possible interpretation: The current odds are 1 in a million, based
on very tentative measurements. Once better measurements are recorded,
it turns out that the odds will become either

1. One in a billion, since the reduced error in measurements are
now significantly less than the predicted "miss"; or

2. Around 99.9 percent, since the predicted "miss" is essentially
zero.

If we think there's a one in a million chance of outcome 2, and the
rest of the time, outcome 1 happens, then our best estimate of the odds
right now is

(999,999/1,000,000)*(1/1,000,000,000) + (1/1,000,000)*(999/1,000)

which is very close to one in a million. Note that it is very likely
that the odds of a collision will drop a lot, but that is balanced by
a tiny probability that it will become a virtual certainty.

Brian Tung
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