Continued from part 1...
If an asteroid larger than a certain threshold hits the Earth, not much will be normal anymore. It will take tens to hundreds of years to recover from such an impact.
What can we do? How could we protect ourselves?
As detection is the first step of being able to survive an asteroid hit, surely we have someone on it? So who is doing the detection now - are governments and supranational entities like UN doing it 24/7, with budgets running up to hundreds of millions of euros per year? Not really. We're talking about small-scale operations running on very small budgets.
For example, University of Arizona runs the Spacewatch. Canada is planning a 2010 launch of a microsatellite which can track NEOs. NASA coordinates a NEO observing program and funds other tracking programs (like the aforementioned Spacewatch). The European Space Agency (ESA) is also running a small special program.
Other than NASA, in a smaller scale ESA and soon the Canadian Space Agency (CSA), it looks like it is mostly private people and astronomers (both career and hobbyist) who fund and/or conduct the tracking efforts and keep the discussion alive.
For example, one notable private organization is The Planetary Society (disclaimer: I'm a member). They're an organization of private people who are interested in space exploration and who want to establish permanent human presence outside of planet Earth. The Planetary Society also conducts effective lobbying in getting these points heard by the (mostly) US (but also international) deciders.
As for NEOs, The Planetary Society approach is threefold: fund researchers who discover and track asteroids (through the Gene Shoemaker NEO Grant program), lobby for increased NEO research funding, and stimulate the development of possible ways to avoid an asteroid disaster (e.g. via the B612 Foundation).
Other than the presented projects and some others, I'm not aware of other major efforts (if you know of any, please post a comment - thanks).
Part 1 talked about cost-effectiveness of asteroid protection. The estimated spending by USA has been around $4 million USD per year for detection efforts - for other countries, even less. However, even in the USA, no money is directly allocated for actually acting against an asteroid threat, should one be detected. As a result, mitigation efforts consist mostly of theoretical discussion of various methods which could be used. An exception is the B612 Foundation who are trying to change the situation by attempting a practical demonstration whereupon they will alter the trajectory of an asteroid. Their target time-wise is to do it by the year 2015.
The situation simply demands more money to improve both the detection and the protection efforts.
For example, the (quite tiny) 4 m diameter meteoroid called 2008 TC3, which recently hit a desert in Sudan, was detected only 19 hours before impact. Although it was identified and tracked, which was an achievement in itself, an early warning 19 hours before simply does not leave time to do anything.
We know for sure that there are big rocks out there, many of which are headed our way. One example is 99942 Apophis, which will pass close to Earth in 2029. At one point in time, it was even believed to impact Earth in 2029, then later the impact date was moved in 2036, but these estimates were later refined even more, and currently the impact probability is very low.
However, it's really is just a matter of time before an asteroid slams into Earth. This threat is real. It is not something imagined like a threat from country X or organization Y. Take your shoes off when you board an airplane, but don't peek at the skies, mmkay.
The bottom line is: money is not an issue (like Mr. Matheny argued, see part 1); technology is not (overwhelmingly) an issue - it's simply about the will to do something about it. As long as we're stuck on this one planet with all our eggs in one basket, we should be vigilantly scouting for the rocks and prepared to act quickly when the time comes. Preparing for a known, real, tangible threat is simply smart from a survival point of view.