Daniel Jackson, Ph.D., is an archaeologist and linguist from Earth, and a member of Stargate Command's flagship team, SG-1.
Jackson played a critical role in the United States Air Force's Stargate project by determining the purpose of the gates' chevrons, which enabled the project to navigate to specific locations. He then accompanied the team that made contact with the Goa'uld and their subject peoples on Abydos. Although he had intended to remain on Abydos, he returned to Earth the following year when his wife Sha're was kidnapped by the Goa'uld Apophis. He remained a member of SG-1 until 2002, when he ascended to avoid death by radiation poisoning.
Following his ascension, Jonas Quinn took Jackson's place, with Jackson walking among the Ascended for over a year before he descended and eventually rejoined SG-1 in 2003.
As such, Jackson remains a member of SG-1 to this day, and is also a veteran member of the team, having served on SG-1 longer than any of its current members, including Teal'c, Colonel Cameron Mitchell and Vala Mal Doran. He is also the foremost expert in Ancient language and history with Dr. Rodney McKay, Chief Science Officer of the Atlantis expedition, presumably a close second to Jackson.
