Don't wanna scare you, but there is problem in understanding with 2012 DA 14

Till I remember, I hope i am mistaken... This is my school time story when we were learning, our professor told me this because my calculation were never correct using formulas.

"JPL program calculates orbit of object on the basis of center of earth and not from the surface of earth. So, every time we see physically and track object we must remove half the diameter of earth in order to locate exact location of visible object always remember to remove radius of earth and atmospheric disturbance in visibility before publishing your figures"

if I apply this reverse logic to 2012DA14. if JPL says object will pass 14000 miles from earth it means it will pass nearly 10000 miles from surface (earth's diameter is 7926 miles approx). However story does not end here as per ecliptic position of 2012 DA 14 it will be coming from below to above horizon, for public viewing it will be coming from south and will pass go to north. This is more bad news as middle as due to gravitational pull on middle of earth (gravity = acceleration) if applied speed of 2012 DA 14 will increase from his predicted speed of 28000 km/h to approx 30500 kms. This is incremental speed will reduce the distance by 9.81% approx between earth and object.

That means from naked eye and visibility point of view this object will pass only 9000 miles from above the earth. No doubt in my mind...

I wish i should be wrong, because this will be most closet asteroid ever in the history then. I am not sure those who have posted this thing in various article saying Nasa says knows this things or not, I just wish to be proven wrong.

Source:
[link to neo.jpl.nasa.gov]
[link to hisz.rsoe.hu]
And my own memory

Still Guys there can not be doom, Object is too small to cause problems, can reach earth and damage may be limited
to hardly 44145 acre land apprx.

Not a big deal, and guys please note that, if it hits it can hit only northern hemisphere and not southern due to ecliptic position of object.

see nasa site for more details...