[MUSIC] Although we don't know when humans first imagined leaving the Earth and traveling into the heavens, we can reasonably speculate this was very early on in history. As you'll read in the summary below, there are no known records of mankind's writing about traveling into space prior to the Anno Domini period. Throughout the late Roman period, there were sporadic mentions of humans traveling into space. But such flights of fancy disappeared during the limited writings of the Dark Ages. The heliocentric theory from Copernicus, published in 1543, stating that the Earth and other celestial spheres revolved around the sun, as opposed to the other way around, served as an important advancement in the understanding of the universe. Galileo's telescope enabling people to see the moon's surface serve to make the dream of space travel more plausible by promoting the understanding that the moon's surface was much like the Earth's. From that point forward scientific writings and literature became increasingly filled with speculations and stories about space flight. In this unit, you'll read about some of the more important historical writings of space travel. As you've learned in this unit, humankind has long had a fascination with the idea of space travel. The early musings on space travel included accounts of how humans were to travel into space. From human powered wings to chairs lifted by birds. As technology developed, writings about possible space flight travel began to incorporate the improvements in technology. It's interesting that many early authors described a variety of creatures in functioning societies, on the moon and other planets. Finally, the idea of rockets makes its way into the literature. And descriptions of space travel begin to resemble the type that occurred during the previous century. Our next unit will focus on early rocketry. [MUSIC]