Throughout history, mankind has wondered what is beyond our own planet. They have gazed up at the stars and made some significant and important discoveries related to the field of astronomy. On our list below, you will find great names listed in order of popularity, like Copernicus, Hipparchus, and Ptolemy, among others. Read about the most famous astronomers of all time and their contributions.
 Nicolaus Copernicus (1473–1543)Famous For: Formulating the heliocentric illustration of the universe The “heliocentric theory” of Copernicus can be found in On the Revolutions of Celestial Spheres. The theory presented the argument that the earth is not the center of the universe, and presented that the Sun directly affects the movement of the planets. |
 Stephen Hawking (1942)Famous For: The “Hawking radiation theory” Using quantum mechanics and the general theory of relativity, he combined the two fields of study to explain cosmology. He also proposed that “black holes” produce radiation, this radiation from the black holes is known as “Hawking radiation.” |
 Galileo Galilei (1564–1642)Famous For: Being the “Father of Observational Astronomy” As the father of observational astronomy, Galileo identified the four moons of Jupiter, observed and provided an analysis of sunspots, and presenting the theory of heliocentrism. |
 Carl Sagan (1934–1996)Famous For: The SETI program and TV series “Cosmos” Carl Sagan made it easy for the ordinary people to understand and enjoy science. Because he described that there “…billions upon billions of stars”, when an enormous quantity of “anything”, is described known as a “sagan.” |
 Johann Gottfried Galle (1812–1910)Famous For: Discovering the planet Neptune While working at the Berlin Observatory, Galle first observed and viewed Neptune, the eighth planet from the sun. Later in his life, he provided methods to calculate planetary orbits |
 Johannes Kepler (1571–1630)Famous For: His work in the field of astronomy and mathematics Acceptance of Kepler’s laws and theories were not immediate. His book “Epitome of Copernican Astronomy” became the main source of his ideas for many in the early 17th century. |
 Michael E. Brown (1965)Famous For: Identifying Pluto as a TNO (trans-Neptunian object) As a professor in planetary astronomy, Brown is credited as the man “who killed Pluto.” He and his team were responsible for the discovery of TNO’s, objects that orbit the Sun beyond Neptune. Eris, a “dwarf planet”, was sitting between Neptune and Pluto, thus making it the ninth, the debate goes on. |
 Tycho Brahe (1546–1601)Famous For: His comprehensive work on astronomical and planetary observations Tycho was popular during his time as both an alchemist and as an astronomer. He was the last remaining astronomers who made his observations using the naked eyes. He did not use a telescope. |
 Christiaan Huygens (1629-1695)Famous For: Providing an explanation for Saturn’s rings The explanation that Huygen’s gave for the rings of Saturn was that it was a solid flat ecliptic ring that touched nothing. His last book, Cosmotheoros, he suggested the possibility of extra-terrestrial life on other planets. |
 Edwin Hubble (1889–1953)Famous For: Having space telescope named after him Hubble made observations of galaxies beyond the Milky Way, his discoveries include Triangulum and the Andromeda Nebula. |
 Thomas Gold (1920-2004)Famous For: The “Steady State Theory” Gold and three of his colleagues a hypothesis related to the creation of the universe that was known as the “steady state theory.” |
 William Herschel (1738–1822)Famous For: The discovery of infra-red radiation and the planet Uranus William Herschel’s fame is based on his identification of Uranus and tow of its satellites, Oberon and Titania. In addition, and perhaps by accident, discovered the existence of infrared radiation when using filters during his observation of sunspots. |
 Joseph-Louis Lagrange (1736-1813)Famous For: The Lagrangian Points In an effort to explain the “orbital configuration” of a small object that is affected by gravity Joseph LaGrange provided a solution in mathematical terms which is known as the Lagrange points. |
 Pierre-Simon Laplace (1749–1827)Famous For: The nebular hypothesis and mathematical astronomy LaPlace is believed to be one of the earliest astronomers to suggest the existence of black holes in space. He also presented a theory that explained the origin of the solar system, the nebular hypothesis. |
 Edmund Halley (1656-1742)Famous For: Having a comet named after him, Halley’s comet Halley calculated the orbit of a comet that could be seen from earth every seventy-six years. It appears again in 2061, if calculations are correct. |
 George Gamow (1904–1968)Famous For: Big Bang Theory The discovery of the explanation of quantum tunneling via alpha decay is attributed to Gamow. Interestingly, he postulated further what has been known as the “Big Bang Theory.” |
 Caroline Herschel (1750-1848)Famous For: The discovery of comets and one named after her, the 35P Herschel-Rigollet Comet Sister of astronomer William Herschel, Caroline discovered and calculated the orbit of a comet known as the Herschel-Rigollet comet. The orbital period of this “periodic comet” is said to be 155 years. In all she discovered five comets. |
 Clyde Tombaugh (1906–1997)Famous For: Discovery of Pluto and asteroids During his time at the famous Lowell Observatory, Tombaugh discovered the planet Pluto and the Kuiper Belt in 1930. He also contributed to science by his discovery of asteroids, fourteen in all. |
 Annie Jump Cannon (1863-1941)Famous For: The Stellar Classification system and the “Harvard Classification Scheme” Annie Cannon developed a system to classify and organize stars according to the temperatures they produced. More importantly, the stellar classification system was also the work of this American astronomer. |
 Charles Messier (1730–1817)Famous For: The Messier Astronomical Catalog Provided astronomers a catalogue that provided information whether an object viewed in space is stationary or moving. This catalogue contained 110 objects, thus it was called 110 Messier Objects, along with nebulae and clusters of stars. |
 Fritz Zwicky (1898-1974)Famous For: The theory of supernova and dark matter It was Zwicky who brought us the word “supernova” and presented a theory that these were stars that became “neutron stars”. He also proposed the theory of the existence of “dark matter” or unseen matter, in space. |
 Jocelyn Bell (1943)Famous For: The discovery of “Pulsars” The first pulsar, a neutron star that produces electromagnetic radiation, was first identified and discovered by Bell. She later discovered three more. |