"We called it the Light. The Light that had raised us from darkness. Using its power, humanity was able for the first time to travel faster than light. We expanded... we were now able to explore and colonize the space. The Light started the Golden Age... the Age of Light."~ Anonymus, 2000 HSC
The Light is the name of the mysterious alien device or mechanism that was discovered on the Moon by the humans on July 20, 1969, somewhere in Mare Tranquillitatis. Most of the knowledge about it was lost and forgotten during the Long Night, but it's assumed that it allowed the humans to access the faster-then-light Travel Network, and it was the device between the expansion and massive colonization of the human race.