Little Green Men (Article 110)
A casual observer may not know what it is, but Mars’ distinctive reddish-brown glow in the night sky, especially when it is closest to us, is hard to miss. Mars regular appearances have been recorded from the earliest times. The Babylonians, about 400 BC, called it Nergal and associated it with natural and man-made disasters. The ancient Egyptians named it Decher, ‘The Red One’. The Romans linked its red glow with anger and called it Mars after their war god, Ares. The name still survives on another star, the legendary opponent of Mars, Alpha Scorpii, or Antares, a red supergiant star, which can be seen low to the South on midsummer nights.
Modern scientific observation of Mars began with Tycho Brahe in the 17th Century, when his close observations of the planet’s movement were used by his student Johannes Kepler, to develop his three laws of planetary motion. Brahe’s observations showed Kepler that Mars, and every other planet, orbited the Sun on elliptical paths, not circular, as had been thought.
Speculation about life on Mars also began about this time. Christian Huygens, and William Herschel were the first to propose the idea. The varied patterns of light and shade on Mars’ surface led them to speculate that the dark areas were seas which may support life. The presence of polar ice caps on Mars was another tantalising similarity to Earth. The speculation about life on Mars increased after 1877, when Giovanni Schiapparelli thought he saw channels, or ‘canali’ etched on its surface. The mistranslation of the word ‘canali’ into English as ‘canals’ misled people into thinking the features were artificial. As the Suez Canal was constructed around this time, most people associated canal construction with state of the art engineering, only possible to an advanced civilisation.
Speculation about the Martian canals was fuelled further by the astronomer Percival Lowell in the 1890s. Using maps he drew of Mars from his telescope at Flagstaff, Arizona, he speculated that the canals were used by a technologically advanced civilisation to distribute dwindling water supplies from the Martian polar ice caps to populated areas of the planet. There were influential dissenting voices, for example E. E. Barnard, a gifted observational astronomer, saw no canals. The astronomer Antoniadi dismissed them as optical illusions in 1909, having failed to find them.
However, the imaginative possibilities of Lowell’s speculations were too much to resist, and sci-fi was born! The power of this genre of literature was demonstrated when a radio adaptation of H. G. Wells ‘War of the Worlds’ was broadcast from New York in 1938, causing panic to many people who thought they were listening to a news bulletin describing a Martian invasion of Earth!
In the end, a space probe ended the speculation. In 1971, NASA’s Mariner 9 became the first artificial satellite to orbit Mars. It found a dry, arid surface more like the Moon than Earth — and no canals.
Next meeting is on Wed. 7th Nov at 8pm in room 206 Mary Immaculate College when Simon Kenny will give a talk on ‘The Electromagnetic Spectrum’
03-11-2007 Little Green Men (Article 110)
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