Lion's Head beacon
The beacon is apparently an artifact left by the Thirteenth Tribe as they made their way from Kobol to Earth, or possibly on a return voyage to leave a map of Earth's night sky on Kobol. It is approximately 3,000 years old .
When the beacon is brought aboard the basestar, it soon infects the Cylons, including humanoid Cylons, Raiders, the Hybrid and the basestar itself. The Centurions, apparently controlled by the Hybrid, began shutting down as the infection progressed.
When the basestar's crew discover that infection might spread into their community via their resurrection process, they immediately quarantine their Resurrection Ship to prevent the reception of any transmitted consciousnesses from the dying basestar. To minimize the risk, Baltar is dispatched to the basestar to investigate. The beacon, as seen by Baltar, appears to have gelatinous material within slats in its interior (Torn).
Later, the beacon is discovered and left behind by a Colonial boarding party after they realize that an infection exists. The beacon is presumably destroyed when the basestar self-destructs (A Measure of Salvation).
- The story behind the Lion Nebula beacon and the virus may have been inspired by the lunar lander Surveyor 3. Before launching in 1967, its camera was accidentally contaminated by a common bacterium. When the camera was recovered by Apollo 12 astronauts, the microbes returned to life, having survived two and a half years of vacuum, radiation, and temperature extremes.
- In the podcast for this episode, Ron Moore explains that writing about the beacon in later episodes would have introduced too much work as the characters would scrutinize and analyze it to the point of affecting the overall story, so it was deemed best to leave the beacon on the basestar in the aired storyline to destroy it and dispense of further commentary on the object.