Today the object with the provisional designation 8TA9D69 was
submitted to impact monitoring by using the normal software of the
NEODyS system, by using the observations as reported by the MPC on the
NEO Confirmation Page.

The results were as follows (this is the Risk file in the usual format)

Object: 8TA9D69

date MJD sigma sigimp dist +/- width stretch p_RE
exp. en. PS
YYYY/MM (RE) (RE) RE/sig
MT
--------------------------------------------------------------------------------\
------------------
2008/10/07.116 54746.116 2.824 0.000 1.91 +/- 0.001 4.01E-03 9.98E-01
6.01E-04 1.69


Based on 26 optical observations (of which 0 are rejected as outliers)
from 2008/10/06.278 to 2008/10/06.643.

Coordinates are given on the Target Plane
Unit is one Earth radius, but impact cross section
has radius between 2.02 and 2.02 Earth radii

The probability of impact is, according to different computations done
in slightly different ways, between 99.8% and 100%; in practice the
impact can be considered sure and is for tonight. Our computation has
already been confirmed independently by others, including the JPL NEO
group (with which we consult in all relevant cases of possible
impact).

The other important result is that the confidence ellipse for the
arrival of this object on the atmosphere is very small, thus it is
possible to predict this atmospheric entry point within tens of
kilometers. Unfortunately we are not equipped to do this computation
on short notice, but others are doing this (some already have).

The effect of this atmospheric impact will be the release, in either a
single shot or maybe a sequence of explosions, of about 1 kiloton of
energy. This means that the damage on the ground is expected to be
zero. The location of these explosions is not easy to predict due to
the atmospheric braking effects. The only concern is that they might
be interpreted as something else, that is man-made explosions. Thus in
this case, the earlier the public worldwide is aware that this is a
natural phenomenon, which involves no risk, the better.

The NEODys team

Andrea Milani, Maria Eugenia Sansaturio, Fabrizio Bernardi, Giovanni B.
Valsecchi

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Andrea Milani Comparetti
Dipartimento di Matematica
Piazzale B. Pontecorvo 5
56127 PISA ITALY

tel. +39-050-2213254 fax +39-050-2213224
cellular phone +39-349-4482751
E-mail: milani@...
WWW: http://adams.dm.unipi.it/~milani/
================================================