That evening the object should be visible with the naked eye. In Europe, where it would be dark by that time, the object should be a splendid sight as it moves from northwest to southeast across the sky over a couple of hours. There is still some uncertainty to the computation. On the one hand, it is possible that 1997 XF11 will come scarcely closer than the moon. On the other hand, the object could come significantly closer than 30 thousand miles.
Further observations are necessary in order to refine the figures.
It is also possible that prediscovery observations of 1997 XF11 can be located on archival photographs. Ephemerides for these times are available. It is hoped that continuing observations will be made during the next few months. The object is starting to move into the dusk and to fade week by week. Nevertheless, it should be quite accessible for a while with large telescopes, which in addition to helping establish whether a collision in 2028 is possible, could usefully provide more definite information about the object's size.