99942 Apophis is a near-Earth asteroid with a diameter of 370 metres. Initial observations indicated a probability up to 2. 7% that it would hit Earth or Moon on April 13, 2029. The asteroid was discovered on June 19, 2004, by Roy A. Tucker, David J. Tholen, and Fabrizio Bernardi. It is the Greek name of Apep, an enemy of the Ancient Egyptian sun-god Ra.
About 99942 Apophis in brief
99942 Apophis is a near-Earth asteroid with a diameter of 370 metres. Initial observations indicated a probability up to 2. 7% that it would hit Earth or Moon on April 13, 2029. By May 6, 2013, the probability of an impact on April 13, 2036 had been eliminated. The asteroid was discovered on June 19, 2004, by Roy A. Tucker, David J. Tholen, and Fabrizio Bernardi at the Kitt Peak National Observatory. It is the Greek name of Apep, an enemy of the Ancient Egyptian sun-god Ra. In the fictional world of the show Stargate SG-1, the alien who lived on Earth had posed as a mythological creature. The name is pronounced with the first syllable accented on the second syllable as the name was pronounced in the TV series. Based upon the observed brightness, the asteroid’s diameter was initially estimated at 450 metres ; a more refined estimate more refined by NASA’s Tokunaga Infrared Telescope in Hawaii is 350 metres. NASA’s impact risk list lists the asteroid at 330 metres and a risk of impact at 350 metres. The highest probability of impact is on April 12, 2068 and the odds of animpact on that date, as calculated by the JPL Sentry risk table using a March 2016 solution, are 1 in 150,000, but the nominal trajectory has the asteroid more than 1 AU from Earth on that Date. On average, an asteroid the size of Apoph is expected to impact Earth once in about 80,000 years.
The odds of impact on that day are 1,000 to 1,200,000 to 1,500, according to JPL’s risk table. It was discovered at a very low solar elongation and at very long range in 2004. When first discovered, the object received the provisional designation 2004 MN4, and early news and scientific articles naturally referred to it by that name. Once its orbit was sufficiently well calculated, it received the permanent number 99942. Receiving a permanent number made it eligible for naming by its discoverers, and they chose the name \”Apophis\” on July 19, 2005. In contrast, the name of the Egyptian god of the same name ispronounced with the accent on the first syllable of the word Apep in the mythological story of the Uncreator, an evil serpent that dwells in the eternal darkness of the Duat and tries to swallow Ra during his nightly passage. ApeP is held at bay by Set, the Ancient Egypt god of storms and the desert, and he had lived during ancient times and was that he had posed a threat to the ancient god of thunder and storms, thereby giving rise to the backstory of the story of Stargate SG-1. In 2008, the keyhole had been determined to be less than 1-km wide. Observations in 2020 by the Subaru telescope have confirmed David Vokrouhlický’s 2015 Yarkovsky effect predictions. Goldstone radar will observe ApophIs March 3-14, 2021 helping to refine the orbit.