Rusty Schweickart (Apollo 9 astronaut) gave an interesting talk back on 2004 on "The Asteroid Threat Over the Next 100,000 Years" [1]. He said that we don't have any technology (space capable nukes, gravity tractors, laser deflection, etc) to prevent impacts. As far as I know this is still true nine years later.
He gave some useful probabilities for the likelihood of impacts with rocks of various sizes over long an short time scales, which puts the risk into context.
He also explained that if you could develop the means to deflect an incoming rock away from the earth, the same technology could be weaponized to deliver impactors towards points on the planet's surface.
Schweickart is involved with the B612 Foundation [2], who are doing work on impact prevention technology. He's co-chair of the NASA Task Force on Planetary Defense [3], which sounds cool.
Why do problems like this only get tackled when there was a close call?
It's the same everywhere. Gun control discussions, nuclear power plant safety, anti-terrorism measures... it's a long list. Suddenly, governments and societies want action and funding there, where before no need was seen, when the actual situation didn't change.
(However, in the case of climate change, it might be just to late to steer things properly when the effects become clear.)
I think the funniest thing is that sure, we can detect an asteroid barreling towards us, but what the hell are we going to do about it? Maybe it's better not to know. Some things are so completely out of our control that knowing it's going to happen could only cause more suffering.
I think the problem is that humans (or most animals, I guess) are just reacting to stimuli around them 99% of the time. So if something bad happens, we tend to waste time and resources making sure that same exact thing won't happen again when life is adapting so much that chances are something new will happen next time.
There's plenty we could do about it if we knew an asteroid was coming. With years of warning, we could use nuclear explosives to deflect it. With days of warning, we could at least evacuate affected areas.
In fact, we are plenty good at imagining disasters that could conceivably happen. Most of them never do; if we put our efforts into imagined disasters, we wouldn't have time to do anything about the real ones. The way we tell which is which is, necessarily, to wait and see what actually happens, then take steps to guard against similar disasters in the future. Reality is smarter than we are. We need to pay more, not less, attention to what it tells us.
The cynic in me thinks it's cheaper for society to just let it happen instead of using tons of money on teaching citizens to get away from windows in the unlikely event of a meteor.
How many citizens do you think would get away from windows if they receive an SMS telling them to? And how many who weren't at the windows would go stand in the window to look at the great shiny thing?
I think there should be something like the WD40 and Duct Tape saying... maybe "All governments need in this world is Media coverage and Committees. Media coverage to make things happen and Committees to prevent things from happening. "
W. Feller's volume II proves the renewal theorem from which we can conclude that the stochastic point process of arrivals of asteroids of some size and larger is a Poisson process, e.g., as in Cinlar's book. Then empirical historical data provides a good estimator of the arrival rate parameter of the Poisson process.
Net, we can know the arrival rate of dangerous asteroids, and, ballpark, it's one each some millions of years. So, we get to f'get about the problem.
He gave some useful probabilities for the likelihood of impacts with rocks of various sizes over long an short time scales, which puts the risk into context.
He also explained that if you could develop the means to deflect an incoming rock away from the earth, the same technology could be weaponized to deliver impactors towards points on the planet's surface.
Schweickart is involved with the B612 Foundation [2], who are doing work on impact prevention technology. He's co-chair of the NASA Task Force on Planetary Defense [3], which sounds cool.
[1] http://longnow.org/seminars/02004/mar/12/the-asteroid-threat...
[2] http://en.wikipedia.org/wiki/B612_Foundation
[3] http://www.nasa.gov/directorates/heo/library/nac/planetary-d...