Apophis was discovered on June 19, 2004, by Roy A. Tucker, David J. Tholen, and Fabrizio Bernardi at the Kitt Peak National Observatory.
On December 21, 2004, Apophis passed 0.0963 AU (14.41 million km; 8.95 million mi) from Earth.
Precovery observations from March 15, 2004, were identified on December 27, and an improved orbit solution was computed.
Radar astrometry in January 2005 further refined its orbit solution.
The discovery was notable in that it was at a very low solar elongation (56°) and at very long range (1.1 AU).
See diagram below:
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 (on June 24, 2005).
Receiving a permanent number made it eligible for naming by its discoverers, and they chose the name "Apophis" on July 19, 2005.
Apophis is the Greek name of Apep, an enemy of the Ancient Egyptian sun-god Ra.
He is 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 Egyptian god of storms and the desert.

Tholen and Tucker, two of the co-discoverers of the asteroid, are reportedly fans of the television series Stargate SG-1.
One of the show's persistent villains is an alien named Apophis.
He is one of the principal threats to the existence of civilization on Earth through the first few seasons, thus likely why the asteroid was named after him.
In the fictional world of the show, the alien's backstory was that he had lived on Earth during ancient times and had posed as a god, thereby giving rise to the myth of the Egyptian god of the same name.

The mythological creature Apophis is pronounced with the accent on the first syllable (/ˈæpəfɪs/).
In contrast, the asteroid's name is generally accented on the second syllable (/əˈpɒfɪs/) as the name was pronounced in the TV series.
Apophis was discovered on June 19, 2004, by Roy A. Tucker, David J. Tholen, and Fabrizio Bernardi at the Kitt Peak National Observatory. On December 21, 2004, Apophis passed 0.0963 AU (14.41 million km; 8.95 million mi) from Earth. Precovery observations from March 15, 2004, were identified on December 27, and an improved orbit solution was computed. Radar astrometry in January 2005 further refined its orbit solution. The discovery was notable in that it was at a very low solar elongation (56°) and at very long range (1.1 AU). See diagram below:
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 (on June 24, 2005). Receiving a permanent number made it eligible for naming by its discoverers, and they chose the name "Apophis" on July 19, 2005. Apophis is the Greek name of Apep, an enemy of the Ancient Egyptian sun-god Ra. He is 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 Egyptian god of storms and the desert.
Tholen and Tucker, two of the co-discoverers of the asteroid, are reportedly fans of the television series Stargate SG-1. One of the show's persistent villains is an alien named Apophis. He is one of the principal threats to the existence of civilization on Earth through the first few seasons, thus likely why the asteroid was named after him. In the fictional world of the show, the alien's backstory was that he had lived on Earth during ancient times and had posed as a god, thereby giving rise to the myth of the Egyptian god of the same name.
The mythological creature Apophis is pronounced with the accent on the first syllable (/ˈæpəfɪs/). In contrast, the asteroid's name is generally accented on the second syllable (/əˈpɒfɪs/) as the name was pronounced in the TV series.
99942 Apophis