During the 20th century humanity came to realize a dream it had since ancient times: the possibility of space travel. Technological innovations, combined with the political climate of the Cold War, made space exploration a reality for the first time in history.
Astronomy is a science that studies celestial objects and phenomena. Humanity has studied astronomy since ancient times. Astronomy, as an orderly pursuit of knowledge about the heavenly bodies and the universe, did not begin in one moment at some particular epoch in a single society. Every ancient society had its own concept of the universe (cosmology) and of humanity's relationship to the universe. In most cases, these concepts were certainly molded by three forces: theology (religion), nature (climate, floods, winds, natural disasters), and the assumed influence of the stars and planets on the fortunes and fate of people and their societies (astrology).
One of the most dramatic moments of the twentieth century occurred on October 4, 1957. The Soviet Union sent a small shiny sphere with four long antennas into space. They called it Sputnik I. Sputnik is a Russian word that means “traveling companion.” The satellite traveled so fast that its ballistic flight continued all the way around Earth.
While the current lunar exploration initiative has been justified as a “stepping stone” toward Mars, human missions to Mars represent a major step up in complexity, scale, and rigour compared to lunar missions.