Scientists have warned that outer space is becoming too crowded with satellites and the debris of dead satellites that might pose danger for the mankind.
The new extraterrestrial threat in the form of space junk hitting earth could be deadly, according to the first International Interdisciplinary Congress on Space Debris held at Montreal's McGill University at the weekend.
Attended by about 80 scientists, space experts, lawyers and satellite company operators from around the globe, the congress discussed the emerging extraterrestrial threat to earthlings.
"Space junk - from the size of a cornflake to a bus - is a new threat to mankind. Over 19,000 big pieces of junk (debris of the dead satellites) have been catalogued to be circling the earth from the height of 110 kilometre to 36,000 kilometre,'' congress chairman and space law professor Ram Jakhu told IANS.
"But there 300,000 other junk pieces of sizes from one centimetre to 10 centrimetre, and millions of pieces less than one centimetre which have not be catalogued and they hurtling through space,'' said Jakhu, who is an alumnus of Panjab University in Chandigarh.
"At the speed of eight to 10 kilometre per second, these junk pieces are hurtling in space at 10 times the speed of a bullet. Even if a small piece were to hit earth, it will be devastating,'' he said.
The Indian-born space law expert said the congress discussed how to prevent space junk pieces from reaching earth and fix responsibility.
According to Jakhu, there are already 380 telecom and military satellites in the geo-stationary orbit - which at 36,000 kilometre above earth makes satellites look stationary.
"Though (dead) satellites can last in the geo-stationary orbit for millions of years, overcrowding would lead to coalitions with new satellites, making them dysfunctional,'' he said.
However, the real danger comes from satellites which are up to 200-300 kilometre above earth as they can become junk in 15 to 20 years, Jakhu said.