Asteroid Danger

One is that serious damage can be done by asteroids as small as 100m
(actually a bit larger than the likely size of the Tunguska
airbuster - place the Tunguska destruction an ellipse of around
2000km2 over just about anywhere in western Europe, eastern Asia or
South America; & watch your pocket calculator melt down doing the
body counts alone); & NASA has no plans to develop the technology to
systematically pick up even a small fraction of these objects. And the additional bummer regarding that from the point of view of this maillist is that 100m asteroids are probably more economical to attempt to mine than are >1km-wide planet-busters.