But thanks to a rare natural phenomenon, the Red Planet is drawing unusually close to Earth, giving sky gazers a truly once in a life time opportunity to get a good look at Mars.

On the 27th of this month, the Red Planet will be 55.76 million kilometers from Earth, according to Belgian astronomer Jean Meeus, who says proximity of this kind last occurred nearly 60,000 years ago.

Like racing cars, the Earth - the third rock from the Sun - has the inside track over Mars, the fourth planet, as they orbit the Sun. Earth takes a nippy 365 days to make a circuit, whereas Mars takes 687 Earth days because it is farther out.

This celestial ballet means Earth whizzes past Mars once every 26 months or so. However, the two planets take a slightly egg-shaped path around the Sun, and this factor mainly determines just how close the encounter will be.

In fact, the next time the two planets will be closer than in 2003 will be in the distant future - in 2287.

Dreams and visions

On August 27, Mars will shine red and orange, not of course as big as the Moon or anything near its size, but certainly as bright as Jupiter, the regal giant of our solar system, ever gets.

Sky gazers have been thirsting for the moment.

"The Red Planet will present a large enough disk for backyard astronomers with good-sized telescopes to discern some of the planet's features, such as the polar ice cap, dark surface features and perhaps even storm clouds," the specialist website space.com says.

Mars has always cast a spell on Earth: either as a divine body, a fictionalised source of invaders, or as Earth's lush twin.

Dreamers see it as mankind's first colony in space, a stepping stone to a wider conquest of the Solar System and, who knows, the galaxy beyond.

"The Earth is the cradle of humanity, but we cannot live forever in a cradle," the Russian physicist Konstantin Tsiolkovsky, an early visionary of interplanetary travel, wrote in 1911.

Planetary probes

No fewer than four new probes - two US, one European and one Japanese - are hurtling towards Mars, with their main goal to resolve the great enigma: Does life, or the potential for it, exist on Earth's neighbour?

Europe's Mars Express passes our
moon en route to the Red Planet

The first of these rendezvous, by Europe's Mars Express orbiter and the Beagle-2 lander it is carrying, is scheduled for December 25.

But even if these missions confirm that Mars holds water - the essential substance for making it a staging post for humanity - many, many years are likely to pass before a human sets a footprint in its dusty surface.

In 1952, the German scientist Wernher von Braun, father of the Nazis' V-2 rocket but also a pioneer of the US space programme, sketched his own ideas for what it would take to get Man to Mars.

Mission impossible?

The big technical challenge then, as now, is that our chemical rockets, designed for orbital flight or at most a trip to the Moon, are just too slow, cramped and fuel-inefficient for a trip spanning tens of millions of kilometers.

At such speeds, the first Martian astronauts would have to spend around six months just to get there; a year or so there to carry out experiments, prepare for the return trip and wait for the planetary alignment to close once more; another six months to get back.

Call it a round trip of two and a half years: an odyssey that would place extraordinary stresses on the crew's mental and physical health, their supplies and equipment.

And so, until a faster technology emerges - NASA, for instance, is dusting off old ideas for nuclear propulsion - Mars will remain a twinkling but forever distant lure.