Noted archaeologist and Grandfather of Dr. Daniel Jackson, who followed in his ancestor's footsteps. Daniel admitted he was not the greatest of Grandfathers, and said he insisted everyone call him "Nick," even his own grandson. Because of Ballard's busy explorations, he never had the time to stop and take the orphaned Jackson as his own, something Nick would later regret.
Ballard had always been interested in the Fountain of Youth mythology, and had made attempts to uncover the truth as to its origins. In 1971 he embarked upon an expedition to Beliz and made a remarkable discovery inside a secure structure: a crystal skull. While looking into its eyes he was surrounded by a neutrino spike which enveloped him and transported him, unknowingly, to P7X-377 where he would see (what he would later coin) giant aliens. In shock, Ballard found himself unable to speak. Thus, the creatures sent him back. He took the skull and climbed out of the pit before it collapsed.
Nick, nor anyone else, was able to explain how the skull was carved from a single piece of crystal against the grain given the technology of the day. He tried for years under controlled conditions to make the skull reproduce its effect, but eventually gave up. With no one believing his wild stories about teleportation to great places and seeing large, vaporous beings, Nick had himself committed to a psychiatric institute in Oregon. Daniel was a regular visitor there until he disappeared into a journey of his own in the mid 1990's.
When Jackson went missing, SG-1 paid a visit to Nick at the institution and brought him to the S.G.C. Through communication via an omni-present Daniel Jackson (who could be seen by Nick because of a similar experience on 377), General Hammond was convinced to send Ballard through the Stargate to the place he saw. This time the team interacted with the beings and the aliens, who recognized Ballard, encouraged him to remain as Earth's representative. Ballard, unlike the others, had already journeyed to the world long ago. SG-1 left Nick to remain on the planet to teach, and learn from, these beings.
Crystal Skull - Nick takes himself out of the psychiatric ward and travels through the Stargate to the world he once visited in 1971.
Evolution, Part 1 - Daniel reveals that one of Nick's early obsessions was trying to locate the Fountain of Youth.