Reply #7: Earth Impact Effects Program

[struggle4progress]

http://www.lpl.arizona.edu/impacteffects/

JPL Small-Body Database Browser
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009%20DD45;orb=1

You can play with the impacts program; if you need better info, maybe the orbital parameters data helps. Crudely speaking: at 10 km from the impact, you're seriously burned by the fireball radiation and also badly battered by the shock wave; at 100 km from the impact, you hear noise and the ground shakes a bit

If this had been on a collision course, I expect that with the limited notice, and lack of precise information about shape and cohesiveness of the object, there would be no chance of gauging with any precision how this would travel through the atmosphere, whether it would break into smaller pieces, and where the largest fragments might hit