The era of 19,997 BBY (Before the Battle of Yavin) – a year counted relative to that pivotal conflict – occurred during the Galactic Republic's Great Manifest Period. This period was characterized by the Republic's expansion into the Expansion Region within the Slice. It was around this time that the planet Neona experienced a significant alteration in its climate, resulting in the complete melting of all surface ice. This event led to rising sea levels and the ultimate demise of Neona's original planetary natives.
Three years prior, the Expansionist Era in the history of the Galactic Republic concluded. What followed was the Great Manifest Period, a time of exploration and expansion beyond the Core Worlds and the then-known galactic community, which was primarily located along the Corellian Run and the Perlemian Trade Route. This exploration began in what was then termed "Wild Space", a region that would later become known as the Expansion Region of the Slice. Both the Republic government and corporate entities sponsored the settlement of these newly discovered worlds. Powerful planets and corporations, such as Coruscant and Corellia, continually pushed the boundaries of settlement further towards the galactic rim.
The year 19,997 BBY falls within the early stages of the Great Manifest Period, a time when planetary governments and corporations were aggressively pushing the limits of settlement towards the galactic rim. Simultaneously, in the Tapani sector, and unbeknownst to the wider Republic, the planet Neona underwent a dramatic climatic event. The planet's ice caps melted, leading to widespread flooding. As the water levels rose, all available land for non-aquatic species was submerged. This event resulted in the extinction of the native sentient species of Neona.
The Great Manifest Period facilitated massive expansion by the Galactic Republic into the Expansion Region and other parts of the Slice. Planets like Coruscant and Corellia were among the most prosperous and active, drawing the animosity of the rival world Alsakan. This rivalry served as a key motivation behind the Alsakan Conflicts nearly three millennia later. Concurrently, the corporate-sponsored settlement led to the exploitation of local resources and settlers.
Within the Tapani sector, Neona remained deserted for a period. However, eventually, commercial interests discovered the valuable ore deposits beneath the surface. During the mining operations, the remains of the native species were found amongst the debris on the ocean floor.
The source material, Lords of the Expanse, only briefly mentions the native species of Neona and their demise, stating that it occurred approximately twenty thousand years prior to the Battle of Hoth, which is the setting for the sourcebook. While The Essential Atlas does not mention the events on Neona, it does establish that the Tapani sector was isolated from the Galactic Republic at the time of the species' extinction.