In early October, a small asteroid, about the size of a VW bug, impacted Earth coming in over Sudan. It was very special. This sort of event happens every several months on average, so just why was this one of particular note?

Because it was spotted headed our way less than 24 hours prior to impact by the guys (and presumably gals?) at the Catalina Sky Survey in Arizona — and then subsequently by many other asteroid trackers around the world. The sum of all this intense telescopic tracking was the first ever predicted Near-Earth Object (or NEO) impact time, impact location and estimated energy. All of which came true — to the extent that it has been check-able.

Now this was of particular interest to a group of us who have been putting together a detailed report for consideration by the United Nations regarding a decision-making process which needs to be coordinated within the international community if we are ever to respond in a timely way to threatened NEO impact.

Of course no one cares about a 1-2 meter diameter asteroid since the atmosphere will protect us by dissipating the energy well above the ground. When they get up to Tunguska size, however, it’s a different story. At around 45 meters in diameter we’re talking 3-5 megatons of energy (250-400 Hiroshimas) and devastating effects at the impact site.

It’s these asteroids, from 45 meters and up, that we need to be prepared to respond to… if we have advanced notice. However, as evident the other night, we’ve now got a nascent early warning system — albeit not well coordinated or securely funded. Furthermore, while no world space agency has yet demonstrated the space technology to deflect an asteroid, the techniques are pretty well understood. In fact, JPL just completed a detailed performance analysis on the gravity tractor concept for the B612 Foundation, and it works just fine. On paper.

So while these two essential legs of a protective triad sort-of exist, the third leg — making a decision to act — is basically nowhere. Who is in charge? Who issues warnings? Based on what information? Who responds to the public’s questions? Who decides who to put at additional risk during a deflection (an unfortunate necessity in the process of deflecting a NEO) and how is liability handled should something go wrong? Who orders an evacuation if it’s too late for a deflection?

Sure, we could leave all this to the emergence of a threat and see how it all settles out in real time. That would be typical of bureaucracy at the domestic level, let alone at the international level. But unlike global warming or many other huge socio-political issues, this one is 1) pretty clear science-wise, and 2) cheap to “solve.” In this case solve = prevent an impact. The trick is that these events happen so infrequently that one has never happened in the lifetime of anyone who will read this blog. Furthermore, action has to be taken 12 or more years prior to a predicted impact and political systems are simply not good at addressing lead times of that magnitude (to understate it!).

Nevertheless our ASE-NEO committee and our international Panel on Asteroid Threat Mitigation have now completed the development of our recommended decision program and submitted it to the United Nations for deliberation and (hopefully) action — eventually. All this starts next spring in the meetings of the UN Committee on the Peaceful Uses of Outer Space in Vienna. They’re expecting our report; it’s built into their 3 year work plan already approved by the UN General Assembly.

Another few episodes like the impact of 2008 TC3 in Sudan will certainly help to emphasize the reality of the threat. And, hopefully, by the time the first one capable of doing actual harm on the ground is predicted to impact, we’ll have something in place to deal with it. If we’re lucky. If not, let’s just hope that it’s a relatively small one and hits in the ocean.

The least that can be said is that now all three legs of the protective triad are “in work.”