When is an asteroid next going to hit the Earth?

Many thousands of objects hit the earth every day.

It is not possible to predict when an asteroid, large enough to cause significant damage, will next hit the earth.
There is no prediction about a specific date. Should any asteroid hit us during the next few centuries, it would come as a surprise. There are general predictions about probability; such as an asteroid above a certain size hitting every so-and-so often (on average).