Mars

The red planet has long been the favoured homeland of extra-terrestrial intelligence. Perhaps it was the eerie red glow or the proximity of the planet that started the speculation, but history is littered with stories of little green men from Mars. One of the earliest accounts was the announcement in 1877 that an Italian astronomer, Giovanni Schiaperelli, had discovered long, narrow "canals". They were thought to be artificially constructed to redistribute water from the planets poles. It turns out that the canals were simply an illusion, created by the eye by combining tiny, disconnected details into lines.

The speculation was not halted by the intervention of modern science. The Viking landers were sent to Mars in 1976 with apparatus designed to look for signs of primitive life in the Martian rocks. They scanned the surface and carried out experiments on the soil but found no evidence of life. More recently a Martian meteorite was found that appeared to have microscopic worm-like fossils embedded in it. The results of the finding have created a great deal of controversy in scientific circles. The debate could finally be settled by a project known as Beagle 2 (named after Darwin’s ship). It is scheduled to travel to Mars early in the new millennium with the aim of independently confirming the implications of the meteorites.

From space, one of the most prominent features of Mars is a belt of three blemishes etched on the surface near the equator. When the Mariner 9 probe arrived at Mars in 1971 to take pictures of the surface, scientists were initially disappointed to find their view was obscured by an immense global dust storm that covered the entire surface of the planet. As the dust began to settle, the spots were the first to emerge from the blanket. Further analysis revealed the spots were peaked with craters, which were and found to be volcanic in origin. They are giants compared to terrestrial volcanoes, the largest reaches 25 kilometres into the Martian sky (three times as tall as Mount Everest) and has a radius of 700 kilometres.

The two moons of Mars, Phobos and Deimos (fear and terror) are named after the horses that pulled the chariot of the god of war in ancient Greek mythology. Both moons are orbiting extremely close to the planet, so close an observer at the poles of Mars would not be able to see them. Phobos completes a full orbit of the planet in less than eight hours, and is getting closer to the surface of Mars every time. Tidal interactions with the planet are causing the moon to lose energy, and it is slowly spiralling inwards towards destruction. Scientists predict that in about 100 million years time it will either be ripped apart by the gravitational interaction or spiral inwards and collide with the Martian surface.