Director General/Executive Director
Remarks at the International Meeting of High-Level Officials Responsible for Security Matters on the General Discussion on Asteroid and Comet Threats
8 June 2012
Ladies and Gentlemen,
The need for security against the possible threat of asteroids and comets-Near Earth Objects- is not only for nations, or regions, it is for the entire planet.
As members of the human race, we all have a joint interest in ensuring the survival of our planet.
Before discussing our potential responses, I should like to provide you with an idea of the nature of the challenge.
There are thought to be between 1.5 million to 2 million asteroids larger than 1km in our solar system; all of them travelling in space at around 90,000 km an hour.
Significant efforts have been made to detect potentially hazardous objects larger than 1km in diameter.
As at 1 December 2011, 832 near-Earth asteroids with a diameter larger than 1km, including 151 potentially hazardous asteroids, have been discovered.
The total number of known near-Earth asteroids of all sizes is 8,397, while the total number of near-Earth comets is 90.
This brings the total number of known objects to 8,487.
Each of these objects can be potentially destructive - if they impact the Earth.
Although it is imprecise, here is a scale of potential destruction based on the object's size:
- If the object is below 50m diameter, the earth's atmosphere will most likely protect us from these objects.
- Greater than 1 km, the object will cause tremendous damage on a regional scale (the equivalent of an atomic bomb impact)
- Greater than 2 kms, the object will produce severe environmental damage on a global scale. and
- Larger still, and it is right for us to discuss the phrase "mass extinction."
But the chances of an impact are very low.
A few smaller objects, less than 30m, enter the atmosphere and burn up as shooting stars every month. However, some objects, as small as 3m in size, make it through the atmosphere to impact with the ground.
NEOs, with a 1km diameter, hit the Earth on average a few times every 1 million years.
Collisions with an NEO greater than 5 kms happen, approximately, once every ten million years.
I am tempted to say we have time, but the laws of probability are an uncertain foundation on which to build our hopes.
A 5km sized NEO could strike tomorrow, with no further strikes for another ten million years.
Regarding prevention, there are various methods that call for the deflection or destruction of an object
Given the consequences of impact, and the huge resources required for prevention, the United Nations has been the key forum to coordinate all our efforts.
In 1995, the Office for Outer Space Affairs held the International Conference on Near Earth Objects at UN Headquarters in New York.
For the first time, the Conference communicated to Member States the potential threat of impact and the need for additional initiatives to detect and track the objects.
Later, the Action Team on NEOs was established with a view to preparing recommendations for an international response to the Near-Earth object impact threat.
There is a work plan to review progress on international cooperation and collaboration on NEO observations to develop a more robust international response.
NEO threat mitigation has three primary components:
- Discovery of threatening asteroids and comets and identifying those objects that pose a threat requiring action;
- Planning a mitigation campaign that includes both deflection or disruption and civil defence activities; and
- If the threat warrants, authorizing the initiation of a mitigation campaign.
These are welcome developments in our approach to this threat.
Ladies and Gentlemen,
Like many security threats, early detection is the key to the catastrophic impact of NEOs. Our era is the first to have the potential to prevent the destruction delivered by one of these objects.
But we should also work to unlock the secrets of these objects. Many NEOs are made up of primordial elements of planets or stars. As a result they may hold clues about how our solar system was formed.
Ladies and Gentlemen,
Asteroids and comets will continue to appear and reappear through out the life of our planet.
As a result, they represent a generational challenge, with the duty of tracking their orbit being handed down to successive generations.
The security of our planet is in our hands, but it is also in the hands of our children and those following long after.
United as nations, united as humans, we are taking important steps towards securing the safety of our planet.
Both myself and the United Nations Office for Outer Space Affairs are proud to be part of this initiative.