The movie Melancholia explains what will happen to YU55

Melancholia is a 2011 science fiction drama film written and directed by Lars von Trier, starring Kirsten Dunst, Charlotte Gainsbourg and Kiefer Sutherland. The narrative revolves around two sisters during and shortly after the wedding party of one of them, while Earth is about to collide with an approaching rogue planet.

source: [link to en.wikipedia.org]


Melancholia, a massive blue telluric planet (or super-earth), becomes visible in the sky, approaching Earth. John, who is keen on astronomy, is excited about the planet, and looks forward to the "fly-by" expected by scientists, who have assured the public that Earth and Melancholia will pass by each other without colliding.

(...)

On the night of the fly-by, it seems like John was right, as Melancholia indeed passes by Earth in a near-miss. After the fly-by, background birdsong abruptly ceases, recalling the falling leaves and dead birds glimpsed behind Justine in the opening frames of the film. Horses calm down from an earlier state of agitation.

However, just as the "dance of death" theory predicted, this is a false respite. As Claire suddenly notices after she views the rogue planet through Leo's makeshift 'planet viewer', Melancholia is circling back and will collide with Earth after all.





Well, well, well...

That's what is going to happen with YU55. It will "fly-by", and everyone will think the problem is "solved".

But the gravity of the Moon will make the asteroid circle back, and start to orbit Earth, in a descending spiraling orbit.

The descending orbit will last 2 or 3 days, and on 11-11-11, the asteroid will impact Earth.