Tuesday, 29 April 2014

Earth 'overdue' for major asteroid impact

Cape Town - The Earth is overdue for a major asteroid impact that could wreak much more devastation if hit a city than an atomic bomb, a new study says.

According to report on The Christian Science Monitor website, a study by the B612 Foundation, a group that aims to map the location of dangerous asteroids, Earth should expect a massive asteroid impact once every 100 years.

These asteroids would pack more power than the Hiroshima atomic bomb "Little Boy" of August 1945. Around 80 000 people were killed by Little Boy immediately and several thousand died from radiation poisoning the months following the detonation.

An asteroid though, could cause as much devastation as 40 of those atomic bombs, or 600kt (kilotons).

There have 26 explosions on Earth between 2000 and 2013 caused by asteroids, the foundation found.

Global damage

The potential impact of a "killer" asteroid was demonstrated in 2013 when a small body struck Chelyabinsk in Russia and injured more than 1 000 people, mainly by breaking glass.

Asteroids typically travel at speeds in excess of 10km/s or 36 000km/h and even impact of a small body of 10m across could result in high localised damage.

Impact with an asteroid 5km in size would cause devastating global damage, and a large asteroid of 10km is regarded as an extinction event, like the one that caused the end of the dinosaurs, 65 million years ago.

Nasa and other space agencies have accelerated their NEO (Near Earth Object) observation capability in an effort to quickly map the orbit of the objects which could cause catastrophic damage should they impact the planet.

The agency recently activated its Wise (Wide-field Infrared Survey Explorer) programme (NEOWISE) which in just 25 days of operation, discovered 857 bodies in our solar system.

While some were known, the programme discovered three new objects hundreds of metres in diameter.

The European Space Agency recently set up the NEO (Near-Earth Object) Co-ordination Centre located at Italy. The facility will monitor objects that could threaten the Earth and is part of the European Space Research Institute.

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