The terrain of the red planet

Email inboxes had been flooded a while ago with messages announcing that Mars would come closest ever to Earth on August 27, 2005. That, of course, was an Internet hoax.

But the real phenomenon takes place next Sunday, when the red planet actually comes as close as 69,448,972 km to Earth ' less than half the distance from Earth to Sun ' making its reddish tinge and polar ice caps visible to the skygazer.

'For Calcuttans, Mars will be visible with the naked eye throughout the night and will be exactly overhead around midnight,' says Debiprosad Duari, director, research & academics, MP Birla Planetarium.

'With a four-inch telescope, one can see the reddish tinge of the planet and the polar ice caps. An eight-inch telescope will allow glimpses of dust storms on Mars,' Duari explains.

Mars draws nearer to Earth because of the characteristics of the orbit of the two planets. Earth goes around the Sun once in 365.25 days, whereas Mars takes around 687 days.

As a result, Earth catches up with Mars every two years and two months and is adjacent to it.

This phenomenon, called 'opposition', finds Mars on the other side of the Sun as seen from Earth and all three in a straight line.

On August 27, 2003, a special kind of 'perihelic opposition' occurred, where Mars came closest to Earth in 60,000 years. The distance had then narrowed down to 55,758,006 km.

The next opposition should have occurred on November 7 this year. However, due to the elliptical nature of Mars's orbit, Earth would be closest a little earlier this time, on October 30.

The Sunday spectacle would be '20 per cent less bright' than the 2003 event, but Mars will still be the brightest thing in the October sky.

'With rains continuing, the only worry could be the cloud cover,' says Duari. 'But since Mars would be visible throughout the night, at least at some point we would be able to catch a glimpse.'