Spaceguard UK is the leading organisation in the United Kingdom devoted to the promotion of British involvement into the international defence programme to identify Earth intersecting comets, asteroids and other space debris with a sole purpose to defend the Earth from potentially catastrophic collisions. Spaceguard UK is located at the former Powys Observatory, UK. The program was established in 1996 to promote and encourage British behaviors involving the discovery and follow up observations of Near Earth Objects (NEO’s).
The threat posed to mankind by the impact of an asteroid or comet is now widely recognised as one of the most significant risks to human civilization, yet there is no coordinated international effort to identify threatening Near Earth Objects or to deal with them once detected.
Over the past decade or so it has become apparent that asteroidal and cometary impacts have played a dramatic, possibly leading role in the development of this planet, and the evolution of life. Natural Science is in the throes of a revolution in thinking, akin to that that occurred after the publication of Charles Darwin’s “On the Origin of Species by Means of Natural Selection”. With this understanding comes the realisation that there is no reason to believe that this extraterrestrial influence is at an end, and the possibility that a major impact could severely disrupt, or even destroy our current way of life on a global scale is one to be considered seriously.
As a result of this ongoing research there is a growing international movement dedicated to quantifying and assessing the risk, and to determining methods of avoiding threatening impacts. While the subject has traditionally suffered from a great deal of scepticism this attitude is now disappearing, and the matter has become one of serious research.
In addition to the Spaceguard UK station there are several other observatories in other countries around the world all dedicated to the identification of NEO’s. A significant contributor to this field of research is the Learmonth Solar Observatory which is located on the North West Cape of Western Australia. Established in 1979, it is jointly managed by the US and Australian governments and is staffed by four different organisations namely the US Air Force Weather Agency, the US National Oceanic and Atmospheric Administration, the USAF 15th Communications Squadron (Maintenance), and the Australian IPS Radio and Space Services. The Learmonth Solar Observatory conducts a project named ‘Wormwood’ which activities are to follow up accurate astrometry measurements that are required to obtain precise orbits for asteroids that have previously been discovered.
So, what is the threat to mankind from space debris whether this be in the form of a comet or meteorite? This brings us onto ‘XF11’. On October 26, 2028, the near Earth Apollo type asteroid ‘1997 XF11’ will make a close approach to our planet. Although initial reports specified an extremely near flight passage, the current data anticipates an approach distance of around 591,000 miles or about 2.5 times farther than the moon. This number sounds like quite a considerable distance from the Earth however, the possible deviation capacity brings this massive object quite close indeed to our atmosphere however, expert opinion suggests that the probability of an impact is very slim.
The newly discovered near Earth asteroid ‘1994 XM1’ made the closest approach to the Earth of any object discovered outside the earth’s atmosphere some 60,000 miles on the morning of December 9th 1994 over Russia. The size of the near miss object was speculated to be around the size of a large house (30 feet or so).
2002 MN – Near Miss
It was commented that ‘2002 MN’ an asteroid big enough to destroy 2000 square kilometers but small enough to escape detection, missed the Earth by just 120,000 kilometers on 14 June 2002. The approach of asteroid 2002 MN was the closest recorded by astronomers since asteroid 1994 XM1 came slightly closer eight years earlier. However, asteroid 1994 XM1 was estimated at only 10 meters across, too small to cause much damage on the ground. Asteroid 2002 MN is estimated to have a diameter of 80 meters, comparable to the object that exploded a few kilometers over the Tunguska region of Siberia in 1908, causing widespread devastation.
The risk of unknown impact therefore appears to be most significant in relation to the smaller objects which may evade detection. It is however comforting that at strategic locations around the world there are monitoring stations (in the main privately funded) to provide us with some degree of advance warnings of these impending devastating objects.