MARS

There are now four planets visible in the night sky. After dusk Saturn shines in the southwest between the constellations Scorpius and Sagittarius. By 9:00 Mars glitters red just above the horizon toward the east. A couple of hours later radiant Jupiter makes his appearance. And finally in the predawn sky brilliant Venus arrives.

Usually the brightest planets are Venus, Jupiter, Mars, Saturn and Mercury in that order. But for a few days around September 22nd Mars actually outshines Jupiter. Not since 1971 has this cold desert planet shone so brightly.

The ancients associated Mars with the darker side of man. Perhaps its red color subliminally suggests blood and evil. Mars was Nergal, lord of the underworld, for the Babylonians. The Greeks called it Ares, the god of War. Mars also reigned over the bloodstained battlefields of the militant Romans.

Mars has long fascinated sky watchers. At the turn of the century the famed astronomer Percival Lowell, founder of the Lowell Observatory in Arizona, was certain there was life on Mars. In a powerful new telescope he saw perfectly straight canals over 100 miles long. He noted the varying color of Mars through the year and attributed the change to the seasonal growth of vegetation. The esteemed Lowell boldly concluded that the canals were built by intelligent creatures to irrigate fields of crops. This conjures up fantastic images of Martian melons, Astral artichokes, Canal corn, God o’ War beets and Cosmic cucumbers.

Scientists using stronger telescopes and unmanned spaceships have dispelled most of the far-fetched Martian notions. The canals are a result of an optical illusion. Humans have a tendency to create order and patterns out of a random array of shapes. That’s apparently what Percival did. The seasonal color change is not from growing and dying plants but is from gigantic dust storms that rage across the planet’s surface. And, with apologies to H.G. and Orsen Wells, no detectable evidence of life has yet been found.

Beginning with Mariner 4 in 1965 a succession of spacecraft has flown by or landed on Mars. The two orbiting Viking spacecraft in 1976 sent Landers (not Ann, but vehicles the size of small houses) parachuting down to the surface. Sophisticated instruments chemically analyzed soil and rocks. The red color of the planet is not from Martian blood but from iron oxide in the soil. Mars is rusty. Other experiments tested for the presence of complex molecules associated with life. The results were negative but far from conclusive.

Close-up photographs of Mars reveal surface features of immense proportions. The tallest mountain in the solar system, Olympus Mons, bursts from the Martian plain. It rises 17 miles, that’s 3 times higher than Mt. Everest! And after growing for a billion years this vast volcano may still be active. You could drop the entire state of Rhode Island into its massive caldera. However I suggest you start with Washington, D.C..

A canyon or actually a series of canyons–3,000 miles long and 13,000 feet deep–rips across the planet’s exterior. This gorge dwarfs the Grand Canyon and would stretch from San Francisco to Philadelphia. Numerous other channels resemble meandering earthly streambeds. This evidence suggests that powerful rivers, larger than any on Earth, once etched the Martian surface.

The prominent polar caps of Mars are frozen carbon dioxide (dry ice) and underneath lies permanently frozen water (permafrost). The canyons, rust and ice all suggest that Mars may once have been a much wetter planet. Where there is liquid water, life can exist. The next spacecraft to visit Mars will continue to search for evidence of past life by performing more sensitive soil analysis.

This month’s exceptional brightness of Mars, caused by the coincidental positions of the Earth, Mars and the Sun, will not happen again until the fall of 2003. Don’t wait until then. Take an evening stroll and enjoy our brilliant sanguinary neighbor.

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Skills

Posted on

August 22, 2009