Near miss path of Apophis with while line been uncertainty or margin of error of its path estimation.
(99942) Apophis which previously known with provisional designation 2004 MN4 was first making massive news in December 2004 after been initial observations indicated a relatively large probability as high as 1 in 37 (2.7%) that it would strike the Earth in 2029, causing NASA to rate the asteroid with Torino scale rating of 4, the first time any asteroid had received a rating above 1, although additional observations provided improved predictions that eliminated that possibility.
According to CNN (link dead), United Nations (U.N.) may be asked to organize an asteroid deflection mission on Apophis and develop a blueprint or plan for a global response to an asteroid threat, including adopt procedures for assessing asteroid threats and deciding if and when to take action.
If any Earth rescue mission is carried out, the favored approach to deal with a potentially deadly space rock such as Apophis is by using Gravity Tractor where a spacecraft will maintain a position near the threatening asteroid and use gravity to alter the asteroid’s course so it no longer threatens Earth.