From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Sun Sep 14 2003 - 08:41:42 MDT
Next year you might want to mark August 27th as the day
you dodged a bullet and offer a toast/sacrifice/etc. to
whatever you think protects humanity.
Why?
Because on August 27th, 1998, a solar flare from the
magnetar SGR 1900+14, which is 45,000 light years away
from us, hit the atmosphere of the Earth and caused a
significant amount of atmospheric ionization [1]. It
is good that it it is 45,000 light years away as only
a small amount of the energy released hit the Earth.
How much energy is this?
Well according to the article a magnetar flare can release
~10^44 ergs. As it turns out, that is precisely the amount
of energy Dyson predicted was required to disassemble the
planet Jupiter [2]. Had it been significantly closer one
couldn't have extracted the the mouses from our dead hands.
Why?
Because there would probably no longer be mouses or hands.
The part that concerns me is that we have little knowledge
of how many magnetars may be much closer to us.
So in terms of the galactic hazard function -- it looks like
one can add magnetars to Gamma Ray Bursts as a significant
component of the hazard function.
Robert
1. http://science.nasa.gov/headlines/y2003/12sep_magnetars.htm?list955064
2. Dyson, F. J., "Search for Artificial Stellar Sources of Infrared Radiation",
Science 131:1667-1667 (3 June 1960).
http://www.aeiveos.com/~bradbury/ETI/Authors/Dyson-FJ/SfASSoIR.html
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