The event, that takes place on the 'Red Planet' once every 1,000 years, has left the scientific community waiting expectantly. Stargazers in the city are gearing up to the prospect of a rare celestial event. Ashlesh D’Souza, member of the Astronomy Club, Ahmedabad, said, "We are all ready with our telescopes to scan the skies for the asteroid. The last such event happened in Siberia in 1908 when it was hit by the astronomical body called Tunguska."

The asteroid was discovered on November 20 this year by NASA-funded Catlina Sky Survey, a body, which is a part of NASA's Near Earth Programme and keeps an eye on astronomical bodies coming close to the Earth.

Dr Arvind Pranjpe, professor at the Inter University Centre for Astronomy and Astrophysics (IUCCA) and a member of the Astronomical Society of India says, "If 2007WD5 indeed crashes onto Mars, it will be a big moment for scientists. The impact of the explosion, and the dust storm it will kick up will all be closely studied. It will give us a chance to study a freshly created crater, which is rare."

The asteroid measures more than 160 feet in diameter is travelling towards Mars at a speed of 30,000 miles per hour, and initial calculations show that it may crash in the equatorial region creating a crater more than one kilometre in diameter.

Scientists and amateur astronomers in India will be praying for clear skies on January 30, Pranpe said. "The previous similar event was the collision of the comet Shoemaker Levy with Jupiter in 1994. In India, we could not witness it because of cloudy skies. We hope that this time things are better. Even the flares of the impact are visible to the naked eye."

The Astronomy Club, Ahmedabad, comprises six dedicated members from various walks of life and is affiliated with similar bodies across the country. D’Souza says, "We are planning to hold a small seminar giving out the basic details of the event so that more and more people can observe it."

At the moment, the asteroid is not visible, being blinded by the glare of the moon. Scientists expect it to be visible sometime in the second week of January, the time around which more accurate data on its trajectory would also be available.