Though a planet suitable for life’s survival could be assembled within 9.2 billion years after the cosmic creation event, nearly another billion years would be required to prepare that planet for primitive life. Beyond that time, it took another 3.5 billion years for the supernova eruptions, dense molecular clouds, gamma-ray bursts, and galaxy-merging events—as well as other dangerous conditions—to subside enough for advanced life and civilization to survive and thrive.
