We may have known a lot – science wise – about comets since
Halley’s Comet’s scheduled return back in 1910, but can anything we don’t know
about comets actually endanger humanity?
By: Ringo Bones
Science-wise, comets pose a real threat to mankind when on
very rare occasions it manages to collide with our planet releasing vast
amounts of kinetic energy. Like the Tunguska, Siberia incident of 1908 or the
suspected comet that hit us 65-million years ago that wiped out the dinosaurs.
Besides kinetic energy impacts, are there other “esoteric” threats posed by
comets to humanity and all life on Earth?
A “comet scare” occurred back in 1910 when Halley’s Comet’s
scheduled return flyby will make the planet Earth pass through its tail stream.
And during the time, it was just recently discovered via spectroscopic analysis
that Halley’s Comet contains vast amounts of cyanogen gas that could poison all
oxygen-breathing life on Earth. By the way, cyanogen gas is a colorless, flammable
poisonous gas that behaves as a univalent radical that is also present in
simple and complex cyanide compounds.
Back in 1910, insurance companies issued a somewhat hastily
formulated comet insurance that was primarily aimed to compensate any loss of
human life and / or livestock in an event of mass cyanogen gas poisoning. But
when planet Earth passed through Halley’s Comet’s tail with no ill effects back
in May 13, 1910 – the idea of comet insurance with cyanogen gas poisoning
coverage was relegated to the more esoteric footnote of history. But does the
cyanogen gas “scare” posed by Halley’s Comet scientifically valid?
During the first decade of the 20th Century, the
science of spectroscopy was significantly way more advanced compared to when
Isaac Newton experimented with its fundamental processes back in 1666. When
Newton discovered that the white light from the Sun was dispersed into a
colored spectrum by passage through a prism.
In Germany in 1814, J. Fraunhofer extended Newton’s
discovery by observing that the Sun’s spectrum, when sufficiently dispersed,
was crossed by a large number of fine dark lines, later known as Fraunhofer
Lines. Terrestrial sources, such as flames, were found to emit bright lines
which were characteristic of the chemical elements in the flame.
Focault – the French physicist – observed in 1848 that a
flame containing sodium would absorb the yellow light emitted by a strong arc
placed behind it. These facts were brought together in 1855 by G. Kirchoff in
his famous law: That the ratio between the powers of emission and the powers of
absorption for rays of the same wavelength is constant for all bodies at the
same temperature.
Kirchoff explained that the Fraunhofer Lines in the Sun’s
spectrum were caused by action of chemical elements in the cooler part of the
sun’s atmosphere in absorbing the continuous spectrum emitted by the hotter
interior of the Sun. Analysis of the Sun’s atmosphere thus became possible. The
method was extended later to stellar spectra and constitutes our only means –
for a time before sample-return robotic spacecraft were invented – of studying
the chemical elements occurring in the stars and other heavenly bodies.
The observation and interpretation of the light emitted by
physical objects – more especially, the interpretation of the light emitted by
excited atoms and molecules in their states might have provided data to
astronomers in the first decade of the 20th Century that Halley’s
Comet is chock full of cyanogen gas. It didn’t, however, predicted that planet
earth could pass through Halley’s Comet’s tail with no ill effects whatsoever.
