First telescopic observation of the night sky

The first telescopic observation of the night sky marked a pivotal advancement in astronomy, conducted by Galileo Galilei in Venice. Utilizing a telescope he had improved, Galileo made groundbreaking discoveries that transformed the understanding of celestial bodies. Among his findings were the Galilean moons of Jupiter, which included Io, Europa, Ganymede, and Callisto. This observation provided evidence that not all celestial bodies orbited the Earth, challenging the geocentric model that had dominated for centuries. Additionally, Galileo's observations of lunar craters revealed that the Moon's surface was not smooth, as previously thought, but rather rugged and uneven. He also documented the phases of Venus, which further supported the heliocentric theory proposed by Copernicus, indicating that Venus orbits the Sun rather than the Earth. These discoveries laid the groundwork for modern astronomy and significantly influenced the scientific revolution, prompting a shift in how humanity viewed its place in the universe.