Asteroid Apophis: A level 4 threat, briefly

An impact with Earth has been ruled out in 2029 for Asteroid Apophis, which was discovered on June 19, 2004.

Alarm bells went off when the initial data suggested there was a fairly large, 2.7 percent chance of the asteroid impacting Earth in 2029. Apophis broke the record for the highest level on the Torino Scale when it was categorized as a level 4 threat -- for a short time -- before it was lowered to 1 and then determined to be of no threat in August 2006.

Nonetheless, the April 13, 2029 fly-by will be quite an event. The asteroid, which is the size of three football fields, will come within 19,400 miles of the Earth's surface, according to the Near-Earth Object Program Office at JPL.

According to NASA and the Near Earth Object Program, we can expect an Earth impact from an asteroid the size of Apophis, around 325 meters, about every 80,000 years or so.

Want to learn more about the devastating effect of an Earth impact? Calculate your chances for survival here.