The biggest threat to earth from Apophis is that is has the slight possibility to pass through a 'keyhole' on its 2029 go round that would set it up for collision in 2036.

My honest opinion is that it will miss...

However a much larger asteroid (101955 1999 RQ36) is coming earth's way in 2182, and will likely hit, with the force of 300 nuclear bombs. The space program is planning to launch a missile to 'readjust' its orbital path in 2100. It is my opinion that they have not closed the space program, but have secretly devoted it to practicing for this event.


[link to neo.jpl.nasa.gov]