The Register is reporting that NASA has started developing a contingency plan to deflect a quarter-mile wide asteroid if indeed it looks to threaten the Earth in 2029. The asteroid formerly known as 2004MN4 has now been named 99942 Apophis. The space agency says that if the asteroid still appears to be threatening Earth by 2013, it will start work on a mission to visit Apophis with a probe in 2019. This would be followed by an attempt to deflect the asteroid some time between 2024 and 2028. NASA's plans to deflect the asteroid were first publicly revealed by the B612 Foundation.