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.