Mars has always had a fascination. In 1877, for example, an Italian astronomer called Giovanni Schiaparelli declared to an astounded world that there was life on the so-called red planet.
Through his telescope he had detected irrefutable evidence to this effect - a strange network of straight lines which he called canali, the Italian word for channels.
Schiaparelli was conservative in his interpretation of these strange phenomena; others, however, were more enthusiastic. Water resources on Mars, they declared, were desperately depleted; the channels were irrigation canals, dug by an intelligent race of Martians to transport the precious liquid from the melting polar ice-caps to the more habitable and amenable lower latitudes of the planet.
Once this idea had taken root, the seasonal changes of colour observed on the Martian surface were interpreted as an annual growth cycle of lichens, rather than the changing patterns of windblown sands that they turned out to be.
We of the space generation have been exploring Mars for more than 30 years, and are less easily fooled. The US Mariner 4 spacecraft was the first to visit the vicinity of the red planet, and in July 1965 it sent back the first close-up pictures of the Martian surface.
Disappointingly, perhaps, Mars turned out to be extremely bleak, with a thin atmosphere providing a barometric pressure at the surface equivalent to that on Earth at a height of about 100,000 feet.
The polar ice-caps, far from being repositories of life-supporting water, turned out to be composed of carbon dioxide, and there were no Martians; the insubstantial pageant induced by Schiaparelli's canali faded and left not a rack behind.
We have paid many more visits in the intervening years. Mariner 6 and Mariner 7 sped past the planet in 1969; Mariner 9 arrived in 1971, and showed us that Mars had a volcano three times higher than Mount Everest, and in 1976 the Viking missions achieved a soft-landing on the Martian surface and carried out many experiments in search of past and present life, but found no evidence that such existed.
Then after a 21-year gap, Pathfinder with its clever little Sojourner robot, landed on the planet's surface in 1997.
Today, if all goes well, marks another milestone in this Martian saga. On January 3rd this year, the Mars Polar Lander was launched from the Kennedy Space Centre, and later today it will land near the southern pole of Mars to disgorge instruments to examine the constituency of Martian soil.
So, as the days go by, we may learn yet a little more about our red mysterious neighbour.