08-12-2007 Mars revealed (Article 115)

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Simon Kenny
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08-12-2007 Mars revealed (Article 115)

Post by Simon Kenny » Wed Feb 04, 2009 11:37 am

Mars revealed (Article 115)

Mars has fascinated earthlings more than any other planet. The fascination increased when telescope studies began in the 17th Century and Mars was thought capable of supporting life. Much of the evidence, taken from fairly primitive instruments, was ambiguous, but this only fuelled the imaginations of astronomers and artists alike. The advent of the space age made it possible at last to check whether the wispy lines seen in telescopes by Schiapparelli and Lowell were canals, or figments of vivid imaginations.

Since the early 1960s a flotilla of spacecraft, mostly American, have either flown past, around or landed on Mars. Both American and Soviet scientists logged a significant catalogue of failed attempts to reach Mars. The first successful mission was in 1965 with NASA’s Mariner 4 which took the first close-up images of Mars, confirming it was a silent cratered world, with a very thin atmosphere and indicating that Lowell’s canals were fictional. Its findings were supported four years later by Mariners 6 and 7. In 1971, Mariner 9 was placed in Mars orbit, the first to do so, and was able to photograph the entire planet, discovering major features such as Vallis Marineris, a vast 4,000km long canyon and Olympus Mons, one of the biggest volcanoes in the Solar System.

The two Viking landers marked a new development in spacecraft design and planetary exploration. NASA sent to both to Mars in 1975. Besides a lander section, each also had an orbiter section to photograph Mars from space and act as a signal relay between Earth and the landers on the surface. The landers sent back detailed images of the surrounding surfaces as well as meteorology data for several years. Their biological experiments on the Martian soil seemed to confirm the presence of organic matter, but these results have since been considered inconclusive.

In the last ten years Mars has received a series of spacecraft with expanding capabilities. In 1996 NASA’s Mars Global Surveyor was launched to survey Mars surface in unprecedented detail. It successfully used Mars’ upper atmosphere to slow itself into a circular orbit to accomplish its main tasks. Since then Mars Odyssey has been put into Mars orbit to study the planet’s geologic and meteorological history and evidence of water resources. In 2005, Mars Reconnaissance Orbiter was launched, carrying the most advanced camera yet to Mars. It will resolve details down to the size of an A4 page from orbit. It has already imaged the Mars Rover ‘Opportunity’ beside Victoria Crater.

Perhaps the most successful probes to Mars are NASA’s rovers ‘Opportunity’ and ‘Spirit’, which landed in January 2004. They still continue to explore craters and rock outcrops on opposite sides of the planet, long after their expected expiry dates. Using innovative techniques in landing and mobility already used in the spectacularly successful Pathfinder/Sojourner Rover mission in 1998, both Spirit and Opportunity continue to return stunning images of their travels on the surface of Mars.

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