by Don Yeomans

NASA’s Near-Earth Object Program Manager

Italian scientist Andrea Milani has announced that the recently
discovered close Earth approaching asteroid 2000 BF19 has a very
small Earth impact probability in the year 2022. Because there is
only 6 days of observations for this object, the most likely scenario
will be that, with additional observations, this impact possibility will
go away. However, a call for additional observations has been made
to verify this likely result. It should be noted that the quoted impact
probability of one in a million is well below the “background level”
of the Earth being hit by a comparably sized asteroid that has not yet been
discovered. The announcement message from Dr. Milani follows:

The automatic close approach monitoring system, set up as an
additional service to the NEODyS system, has detected a case of
‘virtual impactor’, that is an asteroid for which the presently
available observations are not enough to allow us to exclude a future
impact. This happens at a probability level of roughly one in a
million, in the year 2022, and the asteroid is much less than one
kilometer in diameter, thus this should not be rated as a serious
concern (the rating in the Torino risk scale is still 0). The impact
could result by passing through a keyhole in the 2011 close approach;
the encounters would then repeat every 11 years, in a typical case of
‘resonant return’.

Nevertheless, shame on the astronomical community if we lose this
dangerous fellow, which is unfortunately quite dim and fading. The
asteroid is named 2000 BF19. Ephemerides for this object can be found
from NEODyS at

http://newton.dm.unipi.it/neodys/

I would appreciate the collaboration of those among you who have the
capability of observing at magnitudes between 21 and 22; note that the
last observation was from the Italian amateur site S. Marcello
Pistoiese (but Boattini rated it as a lucky shot, with especially good
seeing conditions for our sky).

I apologize for sending out this message without all the necessary
documentation, which will be provided later to allow other orbit
computers to check our computations, but this object is visible
tonight and is fading, so I rate this message as scientifically
urgent.