A known asteroid will pass us close in december 2012 within 0.5 AU give
or take a bit ... I believe theres been others
http://neo.jpl.nasa.gov/neo/pha_ca_date_f.html
The other part of the fairy whisperers well researched facts probably relates to eris
http://en.wikipedia.org/wiki/2003_UB313
One of the most distant known objects in our solar system
Aside all the mythical conotations of its name its 500 year plus orbit
thats very eccentric orbit
does bring it a fair bit closer to us .. but its still
so far away at its closest point you wouldn't believe .
These storys are all made up the same way in that the writers start with an outcome then work back selectively picking up a half truth here and there to make the end result plausable ..imo
welcome and enjoy your stay