Stonehenge, located in England, is believed to have been constructed around 2500 BC and was used for astronomical observations, including tracking the movements of the sun and moon.

Aristarchus proposed that the Earth and other planets revolve around the Sun, a concept known as the heliocentric theory. This idea was later championed by Nicolaus Copernicus in the 16th century.

Tycho Brahe established Uraniborg on the island of Hven in Denmark. It was one of the most advanced observatories of its time, equipped with large instruments for precise astronomical observations.

Galileo Galilei made significant contributions to astronomy, including the discovery of the four largest moons of Jupiter, the phases of Venus, and the sunspots. His observations and theories laid the foundation for modern astronomy.

Greenwich Observatory, located in London, England, was established in 1675 and played a crucial role in the development of astronomy. It became the prime meridian for longitude measurements and contributed to advancements in navigation and timekeeping.

Galileo Galilei is widely recognized for constructing the first functional telescope in the early 17th century. His observations using the telescope led to groundbreaking discoveries, including the moons of Jupiter and the phases of Venus.

Yerkes Observatory, located in Williams Bay, Wisconsin, USA, was established in 1897 and was equipped with the world's largest refracting telescope at the time. It played a significant role in advancing astrophysics and contributed to our understanding of the universe.

The Keck I and Keck II Telescopes, located on Mauna Kea in Hawaii, USA, are the largest optical telescopes in the world, each with a primary mirror diameter of 10 meters. They have contributed to groundbreaking discoveries in astronomy, including the detection of extrasolar planets and the study of distant galaxies.

The Hubble Space Telescope is a reflecting telescope, meaning it uses a curved mirror to focus light. It is designed to observe the universe in visible light, ultraviolet light, and infrared light, providing stunning images and valuable data for astronomers.

Arecibo Observatory, located in Puerto Rico, was a radio telescope with a 305-meter-wide dish. It was instrumental in the discovery of the first extrasolar planets, the study of pulsars, and the search for extraterrestrial intelligence (SETI).

The Atacama Large Millimeter Array (ALMA) is a radio telescope located in the Atacama Desert of Chile. It is designed to observe the universe in millimeter and submillimeter wavelengths, allowing astronomers to study cold gas, dust, and molecular clouds, as well as the formation and evolution of stars and galaxies.

The Event Horizon Telescope (EHT) is a collaboration of several radio telescopes around the world. Its primary goal is to image black holes and their surroundings, providing valuable insights into the behavior of matter and energy in the most extreme environments in the universe.

The James Webb Space Telescope (JWST) is a next-generation space telescope designed to study the universe in infrared light. It is expected to revolutionize our understanding of the early universe, the formation of galaxies, and the evolution of stars and planets.

The Thirty Meter Telescope (TMT) is a planned extremely large telescope to be built on Mauna Kea in Hawaii. Its primary scientific objective is to study the formation and evolution of stars and galaxies, as well as to search for exoplanets and investigate the properties of black holes.