99942 Apophis

99942 Apophis, a near-Earth asteroid and potentially hazardous asteroid with a diameter of 370 meters that caused a brief period of concern in December 2004 when initial observations indicated a probability up to 2.7% that it would hit Earth on April 13, 2029.
== Overview ==
Observations provided improved predictions that eliminated the possibility of an impact on Earth in 2029. Until 2006, a small probability nevertheless remained that, during its 2029 close encounter with Earth, Apophis would pass through a gravitational keyhole of no more than about 800 metres (1⁄2 mi) in diameter, which would have set up a future impact exactly seven years later on April 13, 2036. This possibility kept it at Level 1 on the Torino impact hazard scale until August 2006, when the probability that Apophis would pass through the keyhole was determined to be very small and Apophis' rating on the Torino scale was lowered to zero. By 2008, the keyhole had been determined to be less than 1 km wide. During the short time when it had been of greatest concern, Apophis set the record for highest rating ever on the Torino scale, reaching level 4 on December 27, 2004.
Category:Asteroids
Category:Potentially Hazardous
Category:Aten
Category:Near Earth Object
Category:Other Spectral Types
Category:Geoasteroid