Even though 2012 DA14 comes so close and is relatively large (about half the length of a football field), it is not going to become bright enough to be seen with the naked eye. Sky watchers can catch a glimpse of it using binoculars.
The object will be visible through binoculars for about four hours between 18:00 and 22:00 GMT. It is best seen from Australia, Asia and Europe and will be travelling quite quickly for a celestial object, crossing an area of the sky as wide as the full moon roughly every 30 seconds.
Source: The Guardian