dying from asteroid strike

Newsgroups: alt.folklore.urban
From: Kevin Laws 
Subject: Asteroids and Airplanes
Date: Thu, 20 Jan 1994 13:09:01 MET

I promised a couple of days ago to find the issues of The Economist which 
discussed the chances of dying by asteroid strike. It doesn't, as it turns
out, address the chances of dying by airplane crash, but you can make the
comparison.

The following is from "The Economist", September 11, 1993:

"A report to America's Congress in 1992 by a panel of experts said that if 
there were such an impact, a quarter of the world's population would die. If
the annual risk of the impact is one in a half a million, that gives an
annual risk ofdying of one in 2m, and a lifetime risk of 1 in 30,000...
For Americans, that is higher than the risk of dying in any other sort of
natural disaster."

They go on to admit that this is a lopsided comparison, since we are comparing
a once in a 1/2 million years event with disasters of the last few decades.
They then use a different method of calculating the statistic:

"It would be nicer, for those who calculate the benefit defences [sic...remember,
they're British - KL] might bring, to have a figure for the number of deaths. The
1 in 2m risk can be turned into an equivalent annual death-rate of 2,700 worldwide,
390 in the rich countries."

Given that statistic, you could probably find the rich-country rate of death due
to airline disaster and make a direct comparison. It sounds to me like the 
Independent is making an extrapolation based on similar figures.

However, the Economist points out later that this is based on two assumptions.
First, they say, "the actual death rate from asteroids is zero." Thus, the 
chance of the Earth being hit by an asteroid of a large of enough size to
do real damage is purely theoretical (though there are some good reasons
to believe that their estimate is accurate).

Second, there is still some debate over whether the dinosaurs were actually
wiped out by the asteroid strike as opposed to other effects. Thus, the size
of the asteroid they are using for calculation purposes may not be sufficient
to do the damage they are calculating. It might have to be a much larger
asteroid to do that type of damage.

So, make of it what you will. If you grant their assumptions, then it looks
like the figure in the Independent is correct.

Kevin "hopefully not the first victim" Laws

January 25, 1995