I have been reading a lot on the potential for an asteroid to impact the Earth. The likelyhood of this happening in the near future may be slim but without proper solutions and procedures in place it may difficult to stop an asteroid even in the future.

There have been many impacts on Earth in our past. In fact, approximately 160 impact sites have been identified on Earth so far. These impacts are not only from our distant past, one incident happened only a hundred years ago near the Podkamennaya Tunguska river in Krasnoyarsk Krai, Russia. This blast decimated the area of about 830 square miles. With this kind of destruction occurring as recently as a hundred years ago it is a wonder that preventive measures have not been taken to mitigate this risk.

 As of today there are no procedures in place on a global level to deal with the threat of an impending asteroid impact. The UN will be meeting in 2009 to discuss possible protocols and procedures to deal with an impending impact. This will only begin to address the issues of which agencies will be tasked with developing and implementing anti-asteroid measures. Today, NASA is tasked with locating and identifying NEOs (Near Earth Objects) or objects that have a trajectory that brings them close to the Earth. With many NEOs already discovered there needs to be a focus on how to deal with these if a trajectory leads one of these objects on a collision course with Earth.

Many scientists agree that trying to deflect the object is a better idea than trying to destroy the object. Many of us are familiar with the Hollywood movies depicting a space shuttle blowing the asteroid to pieces with nuclear weapons. Blowing the asteroid up could result in several large pieces impacting the Earth, creating widespread destruction. Even smaller asteroids (measuring 500 meters) can destroy a city depending on the composition.

There are several options that are currently being discussed by scientists, one of them being a kinetic impacter. This kinetic impacter is simply a spacecraft that would collide with the asteroid to knock it out of the trajectory that would lead it close to the Earth. This is probably the best option that is currently on the table as is doesn’t involve nuclear weapons, whose use is currently prohibited in space. Other scientists have suggested using lasers or sunlight to heat the asteroid. Heating the asteroid would then cause the asteroid’s outer layers to expel off of it in turn changing the trajectory.

Some scientists argue that using focused solar heat or lasers are a risky venture as they would need considerable time to heat the object. Time is not the only factor in these proposals, there is also the issue of size. If the asteroid is too large the heating could take even longer, not allowing enough time to change the trajectory of the object.

Even with the options we have there is no organization that has the authority to deal with this issue. Hopefully this will change in the near future; our very survival may depend on it.