Asteroid collision threat to Earth

Press, 29 April 1981, Page 21

Asteroid collision threat to Earth

An undetected asteroid hitting the Earth might be mistaken for a nuclear attack and trigger a nuclear war, according to American space programme advisers. The Advisory Council of the National Aeronautics and Space Administration says in a report that any of about 800 big asteroids now whirling through space would probably “wipe out the human race” if they smashed into the Earth. The council said that smaller space bodies, such as meteors, could destroy big cities on ’impact or trigger a nuclear

war by causing people to believe a surprise attack had [ just begun. i The group urged the ; United States Government to . organise a “project spa- [ cewatch” to keep track of * asteroids and meteors and, if I necessary, send spacecraft I armed with hydrogen bombs > to deflect them. The report , did not estimate the probi ability of the Earth being - struck by a sizeable space

body, but it said that many scientists now believed such an Earth-asteroid collision caused the extinction of the dinnosaurs 65 million years ago. The council said that an asteroid 80 feet in diameter — more than large enough to cause havoc — enters the Earth’s atmosphere about once a century. An asteroid colliding with the Earth would be likely to produce a

huge dust shroud that would block out the sun, destroying plant life and ultimately mankind The craft required to deflect such a body must be able to attach itself to the asteroid, measure its location, then blast it off course by triggering its armament, the council said. It added that such a mission could be done with existing technology and urged that the

United States should conduct a practice mission on an asteroid expected to approach Earth in 1985. “Entire cities could be wiped out by smaller meteors and the density of cities is rapidly increasing,” the report said. In his research on dinosaurs published two years ago, the Nobel prize-winning

physicist, Luis Alvarez, said he had found deposits of iridium, a metal common in space objects, but unusual on Earth, during excavations in Europe and North America. These deposits were formed during the geological period when dinosaurs became extinct. A growing body of scientists accepts this as evidence that a large asteroid struck the Earth, disintegrated, and was scattered to the winds, along with other dust that blocked the sun’s rays for many years.