Mars Moves in on Earth

It's a rarity of rarities, and it has got planetary enthusiasts the world over in an orbital spin. On Wednesday at 10:51 UTC, Mars will officially be a 'mere' 55.76 million kilometers (34.65 million miles) from neighboring Earth, which is closer than it has been since the time of the Neanderthals.

The big red planet has been slowly moving in on Earth for the past few months, and has been visible as a bright orange object in the night sky for many weeks already, outshining everything else in the firmament but the Moon and Venus. With a clear sky and a small telescope, Mars fans should be able to make out surface details of the planet, such as its southern ice cap.

Out of orbital sync

The scarce nature of this neighborly visit is written in the stars. Like a racing track, the orbital paths of Mars and Earth run roughly alongside one another, with Earth on the inner track on a more-or-less circular orbit and Mars on a more elliptical path around the sun. As they are never quite in sync, Earth overtakes the red planet once every two years and two months, and once in a blue moon they simultaneously hit the point in their tracks which are closest to one another.

According to scientific calculations the last time the planets were actually so close was on September 12 in the year 57,617 before Christ. And although there have been other close encounters since between then and now, none have been quite so dramatic as this one.

Scientific advantage

Renowned for their astonishing ability to calculate and predict, scientists have been gearing up for this planetary brushing for some time. Earlier in the summer, NASA launched two new rovers for the exploration of the mysterious planet. The identical rovers, which are due to land in two different locations on the planet in January 2004, are equipped with a set of sophisticated instruments to help determine whether climatic conditions at the Martian sites could once have been favorable enough to support life.

The European Space Agency also launched a Mars probe in the summer. Beagle 2 is due to land on Mars some time in December, where it will begin an exploration of the planet's atmosphere, surface and sub-surface, gathering information about the air with a gas-sniffing 'nose' and about the physical make-up of the planet with samples from below the surface.

Endless fascination

Mars has long been a source of fascination for us earthlings. Since the first close-up pictures of the red planet in 1965, spacecraft voyages have repeatedly revealed a world with strange and distant familiarities, which have keep scientists hooked and anxious to find out more.

What they already know is that Mars, like Earth, has polar ice caps and clouds in its atmosphere, seasonal weather patterns, volcanoes, canyons and other recognizable features.

And although they also know that conditions there are far colder and more sterile than those on our own highly-evolved planet, scientists are now certain that there are great lakes of ice trapped beneath the ground. Ice means water and water means that one day in the distant future, there may be a way to plant life on Mars.