K.A.Cassimally is the editor in chief of Astronomy Journal, a small publication of the RCPL Astronomy Club, Mauritius.Here is the new website(to be launched in February 2004): http://www.rcplastronomyclub.zik.mu
Earth, 'our mother planet', is being attacked everyday by about 25 tons of dust and sand-sized particles. An asteroid, the size of a small car, hits Earth's atmosphere about once in every year.

Fortunately she knows how to defend herself. When that small car-sized asteroid enters her atmosphere, she burns the asteroid up before the latter touches her surface. So no damage is done.

But what exactly are asteroids? Asteroids are fragments from the formation of the Solar System some 4.6 billion years ago. Fortunately, most asteroids are found in the Asteroid Belt found between the planets Mars and Jupiter, the gas giant. Scientists think that asteroids found in the belt can be as big as 940 km across.

Like everybody though, Earth cannot cope with each and every one of the asteroids.

If an asteroid has managed not to be completely burned up while sprinting into Earth's atmosphere, then ???? Scientists think that the collision would cause local damage to the surrounding area.

If that same asteroid however measures more than 1 km across when it touches Earth's surface, disaster is on its way. Scientists believe that this impact could have worldwide effects. Man however is helping or trying to help our mother Earth.

Astronomers are now observing and tracking asteroids, which are at an average distance from Earth to Moon. By immediately tracking potential dangers and learning more about their orbital paths, scientists have more time to study potentially threatening situations. In the next few years, NASA hopes to discover more than 90% of all Earth's threatening objects larger than 1 km across.

But we have to stop these threatening asteroids from hitting Earth so as to 'save' ourselves.

In some movies, we see a missile being launched straight towards a big asteroid. The latter then explodes and the film usually ends. But in reality, it's not that simple. Did you ever think what might happen to the biggest remains of that big asteroid? Maybe it would go and enter Earth's atmosphere or maybe not. If it does pass this first test, maybe it will cause big damages or maybe not. You will agree with me that man cannot take such a risk.

An idea suggests that if a small asteroid is indeed intending to hit Earth, an engine is to be anchored in it. This engine is simply going to push the asteroid away.

Yet another strategy to put the asteroid out of the way is to attach solar sails to it. The 'gentle' pressure of sunlight on the sails will deflect the asteroid away from Earth.

Luckily an asteroid the size of a football field manages to hit the Earth only every thousand years or so but mind you I do not know when such an asteroid did hit Earth last.

About the Author

K.A.Cassimally is the editor in chief of Astronomy Journal, a small publication of the RCPL Astronomy Club, Mauritius.
Here is the new website(to be launched in February 2004): http://www.rcplastronomyclub.zik.mu