Here's the issue, it's a minutely small chance to begin with. We have a very limited space budget as it is with people not even wanting to do real research into anything space anymore. So we're going to use what money to fund this? What telescope time are we going to use?
Small chance - sort of.
We had an airburst over Tunguska a bit over 100 years ago, and that flattened a large swath of forest. Now we just saw another airburst that caused a good bit of damage.
Yes, those are small objects, with relatively low consequences. Maybe "just" a city lost if they'd hit.
The other half of that coin of risk is the consequences. There's a low risk of it happening during our lifetime, high risk of it happening at all, and potentially-cataclysmic consequences if it
does happen.
We can't take away what little resources we have for scientific research and development on space to fund wackadoo shit like this. If you can find a way to fund it then I'll be all for it, but it's not going to get funded by the government. Maybe universities or some fund. The only way the government is going to fund it is when something does hit the planet and kill tons of people. Had that rock in Russia hit a city and killed thousands then maybe, or maybe stamp Al Qaeda on it. Then NASA and these kinds of projects get funded. Maybe more telescopes and equipment get sourced.
I'd love for all the wasted money and computer time to be used on this than something stupid like SETI, so maybe that can happen, I just don't see it nor support it coming out of NASA's already small budget.
1) Development of the technology to detect and deflect asteroids would surely lead to benefits for us. Flying people to the Moon and back would seem to have few practical benefits, but it was an excellent PR campaign for the STEM fields. "Defend Earth and humanity from deadly space rocks!" Maybe it won't attract quite the attention as a Moon shot, but it's still something to get people interested in those fields, and likely generate some interesting new technology and scientific knowledge.
2) Who says NASA's budget will be decreased? This could just as well boost their budget considerably. Now, yes, you'd have to watch
how that budget is allocated; I'd also hate to see things like the missions to Mars or Jupiter's moons suffer as a result. Those produce valuable findings as well.
The only way the government is going to fund it is when something does hit the planet and kill tons of people.
....Yet you're here saying that we'd be wasting money if we'd try to prevent that very thing.
So is your ideal route to a good asteroid deflection program to simply wait until something hits us good and hard, wipes out 10% of the population, and
then try to figure out how to prevent the problem again? Of course, if our ability to launch any manner of spacecraft was destroyed or disabled during the impact, I guess there'd be no point to even
starting research on a deflection project until launch capability was restored. :hmm:
Here's an interesting after action report from a role play NASA and other gov't agencies conducted in 2008 about an object hitting earth.
Ive really only skimmed so far it but they mention at one point 7 years advance warning of something hitting earth was way to short of time, and 15 years or even longer was better.
http://neo.jpl.nasa.gov/neo/Natural_Impact_After_Action_Report.pdf
Yeah...momentum's a bitch.
Let's convince a 150-ton rock, moving at 50,000mph, that it really needs to stop moving in the particular straight line that it's on.
That's going to take a lot of effort.