99942 Apophis Close Encounter with Earth, Friday 13 April 2029

99942 Apophis, (previously known by its provisional designation 2004 MN4) is a near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a small probability (up to 2.7%) that it would strike the Earth in 2029. Additional observations provided improved predictions that eliminated the possibility of an impact on Earth or the Moon in 2029. However, a possibility remained that during the 2029 close encounter with Earth, Apophis would pass through a gravitational keyhole, a precise region in space no more than about 600 meters across, that would set up a future impact on April 13, 2036. This possibility kept the asteroid at Level 1 on the Torino impact hazard scale until August 2006, when the probability that Apophis will pass through the keyhole was determined to be very small. Apophis broke the record for the highest level on the Torino Scale, being, for only a short time, a level 4, before it was lowered. Its diameter is approximately 270 meters (885 ft). As of October 7, 2009, the odds of an April 13, 2036 impact are considered to be 1 in 250,000.

Physical characteristics
Based upon the observed brightness, Apophis' diameter was initially estimated at 450 metres (1,480 ft); a more refined estimate based on spectroscopic observations at NASA's Infrared Telescope Facility in Hawaii by Binzel, Rivkin, Bus, and Tokunaga (2005) is 350 metres (1,150 ft).
During the 2029 approach, Apophis' brightness will peak at magnitude 3.3, with a maximum angular speed of 42° per hour. The maximum apparent angular diameter will be ~2 arcseconds, so that it will be barely resolved by telescopes not equipped with adaptive optics.

Discovery and naming
Apophis was discovered on June 19, 2004, by Roy A. Tucker, David J. Tholen and Fabrizio Bernardi and the Kitt Peak National Observatory. Precovery observations from March 15, 2004, were identified on December 27, and an improved orbit was computed. Radar astrometry further refined the orbit.
When its orbit was sufficiently well calculated, it received the permanent number 99942 (on June 24, 2005). Receiving a permanent number made it eligible for naming, and it received the name "Apophis" on July 19, 2005. Apophis is the Greek name of the Ancient Egyptian enemy of Ra: Apep, the Uncreator, a serpent that dwells in the eternal darkness of the Duat (earth's middle) and tries to swallow Ra during His nightly passage. Apep is held at bay by Set, the Ancient Egyptian god of Chaos.
On13 April 2029 it will become as bright as magnitude 3.3 (visible to the naked eye from rural as well as darker suburban areas, visible with binoculars from most locations). This close approach will be visible from Europe, Africa, and western Asia. As a result of its close passage, it will move from the Aten to the Apollo class.

Orbital characteristics:-
Epoch January 4, 2010 (JD 2455200.5)
Aphelion 1.0987 AU
Perihelion 0.74604 AU
Semi-major axis 0.92241 AU
Eccentricity 0.19121
Orbital period 323.58 d (0.89 a)
Average orbital speed 30.728 km/s
Mean anomaly 339.94°
Inclination 3.3315°
Longitude of ascending node 204.43°
Argument of perihelion 126.42°
Music: Butterfly by Katalin

Видео 99942 Apophis Close Encounter with Earth, Friday 13 April 2029 канала Kurdistan Planetarium