However, on average, one car-sized object enters the atmosphere per year, causing a visible fireball in the sky, and about once every 2,000 years, a soccer field-sized object hits the Earth and does local damage. The concern of the new project is with much larger threats, because every few million years or so, an object miles wide strikes and does global damage. Such a collision occurred about 65 million years ago, causing the Cretaceous–Tertiary extinction, which killed about half of all animal and plant species.
The largest contractor currently participating in NEOShield is EADS Astrium, a corporate giant with 2009 revenues of €4.8 billion and 15,000 employees in France, Germany, the United Kingdom, Spain and the Netherlands. Others include Spanish satellite company Elecnor Deimos Imaging; along with the German, French and Russian Space Agencies.
The leading proposals for avoiding a collision include using a spacecraft to nudge an asteroid off its course, either by physically striking it, firing nuclear weapons at it, or towing it with a tractor beam. Destroying an asteroid is thought to be counterproductive as it would produce a shower of smaller, but still dangerous, objects still on a collision path. Whichever of these options is proposed by the NEOShield project, the result will be contracts worth billions of dollars for many years to come, as the science to actually achieve any of them is decades away.