Nov 07 Congressional Hearings on NEO Survey Programs

This link adresses many of the questions asked below including the cost benefit analysis of an improved search. Please note the current program targeting objects > 1 km retires 90% of the risk associated with PHAs. The A in PHA is for Asteroids and does not include comets which do not currently come close to earth. The proposed improvement to find 90% of objects down to 140 m retires another 9 % of the risk. Continuing operations beyond the goal year of 2020 would continue to incrementally reduce the risk from PHAs beyond 99%.

In the past I have read that the risk from comets constitutes 10 to 30% of the total impact risk which leaves significant risk even after most PHAs are detected.

My understanding is that the reduction in risk from 140 m to 1 km objects during the first year alone of a program capable of detecting 90% of > 140 m objects by 2020 balances the cost of the program. I believe that means the reduction in risk from background chance of an impact in the size range from 140 m to 1 km over the first year times the estimated average cost of such an impact would equal the 15 year cost. If so, the program would pay for itself actuarily several times over by the time it was completed. That sounds like a good investment to me.

The good news is that if both LSST and Pan-STARRS are fully developed and used part time for asteroid searches as intended we would find 90% of the > 140 m objects by 2026. I believe that calculation doesn't include any assistance from the planned discovery channel telescope at Lowell observatory which will also be a big step up from current programs (ten times the discovery rate of all current programs combined) but is significantly less capable than the other two. The bad news is that while 99% of the actuarial risk (chance of impact induced property damage and lives lost) would be retired, the event based risk would still be significant as more frequent tunguska class blasts come from objects < 140 m and the consequences would still be a major disaster in the unlikely event one were to occur over a densely populated area (population density map). Hopefully the more advanced programs mentioned above would provide a fair measure of evacuation warning based on the recent success in predicting an airburst.

They're Coming!
DCT
Pan-STARRS
LSST

Regards,
Mark