OPEN MINDS

Cosmic challenges to our life on earth

Asteroid Tb 145, dubbed the ‘Halloween Skull’ because of its resemblance to the human skull, will whiz past our planet on the night of November 11, just after Halloween. It is a grim reminder of the threats planet earth faces from outerspace. Since its formation over five billion years ago, earth has been hit many a time by asteroids and comets whose orbits bring them into the inner solar system.

There is no doubt that sometime in the future earth will suffer catastrophic cosmic impact. The dangers posed by these cosmic intruders in the inner solar system are now the subject of serious scientific investigation.

The threats of dangerous asteroids, capable of global disasters are extremely rare. The threshold size of half a kilometre could pose a monumental threat on impact. This could cause global mortality and wipe out civilisation.

There is a worry that the estimates of the likelihood of a hit are always based on the currently recorded detection rate, when it is quite obvious that more and more deadly debris is being detected as technology improves. There are huge, almost moon-sized asteroids lurking out in the cosmic highway. A collision with them will produce an impact that could end life within a few hours.

Space debris measuring from 50 to 100 metres impact at speeds that can produce explosions thousands of times greater than mid-size nuclear explosions.

Scientists have spotted about 800 asteroids, rocky celestial bodies, with a diameter of 100 metre moving along circumsolar elliptical orbits. However, they may be as many as 2,000 large asteroids, and some 135,000 rocks with a diameter of 100 metre and more. In March 1989, a 300 metre asteroid crossed the terrestrial orbit and missed the earth by six hours.

The technology to intercept and destroy renegade space matter is no longer a Hollywood myth. Unless we prepare for deep impact, we surely will become extinct like the dinosaurs of ages gone by.