It's tiny, it's coming fairly close but at a safe distance, and even if it were to were to come at us rather than nearly 230,000 kilometres away, this approximately one to three metre long rock, named RZ53, would probably burn up in the atmosphere. Very little if anything would reach the ground – but it isn't heading for us anyway. More detail is available here.
This animation shows its trajectory, passing by at 2220 hours GMT (forty minutes before midnight current British time) tomorrow night (Wednesday). The asteroid is so small that it was first spotted just a few days ago!