Historical Astronomers Timeline

Historical Astronomers Timeline

Kepler

Copernicus

Newton

Galileo

Brahe

Ancient Astronomy

Modern Astronomy

Einstein: 1879 CE - 1955 CE Einstein is most known for his theories of relativity. His first theory was the Special Theory of Relativity which explained the nature of light. His General Theory of Relativity explained gravity and spacetime.

Hubble: 1889 CE - 1953 CE Hubble observed that galaxies recede from each other at a rate that remains proportional between distance and speed. This rate is called Hubble’s Constant which is being exactly measured by the Hubble Telescope to this day.

Oort: 1900 CE - 1992 CE Jan Oort was the first person to measure the distance between our solar system and the Milky Way Galaxy. He also calculated the mass of the Milky Way Galaxy and discovered the Oort Cloud that surrounded our solar system.

Sagan: 1934 CE - 1996 CE Carl Sagan popularized astronomy among ordinary citizens. He has also increased our knowledge of planetary atmospheres and surfaces. He also proposed the idea that there may be life on Jupiter’s Moon, Titan.

Hawking: 1942 CE - Stephen Hawking discovered that black holes emit radiation and could eventually combust by combining the general theory of relativity and quantum theory. He also written many books that publicize many astronomical concepts.

Aristotle: 384 BCE - 322 BCE Aristotle was an ancient greek philosopher who determined that the Earth is spherical, however, he did create a false geocentric model that was believed for centuries.

Aristarchus: 310 BCE - 230 BCE Aristarchus was the first astronomer to create a heliocentric model of our solar system. This astronomer also tried to measure the relative distance between the sun, earth and moon but failed as he lacked the proper technology.

Eratosthenes: 276 BCE - 194 BCE Eratosthenes was able to closely calculate the circumference of Earth. He also invented the armillary sphere to predict star movements and he created a catalog of 675 stars.

Hipparchus: 190 BCE - 120 BCE Hipparchus was able to closely calculate the distance from Earth to the moon as well as creating a catalog of about 850 stars. He also discovered the tilt of Earth’s axis and was able to measure the relative brightness of stars.

Ptolemy: 85 CE - 165 CE Ptolemy created an entire model of our solar system know as the Ptolemaic system. His model was geocentric and was accepted for 1,500 years until Copernicus was able to create his own model.

Ptolemy

Aristarchus

Eratosthenes

Hipparchus

Aristotle

Einstein

Hubble

Sagan

Oort

Hawking

Astronomical Revolution

Copernicus: 1473 CE - 1543 CE Copernicus created a heliocentric idea of a universe that was seen as false until Galileo and other astronomers were able to prove it. He also showed that planets orbit is circles instead of ellipses.

Brahe: 1546 CE - 1601 CE Brahe built his own observatory that he used to create a catalogue of over 1,000 stars. He also created his own model of the universe where planets orbited the sun and the sun orbited earth.

Galileo: 1564 CE - 1642 CE Galileo Galilei discovered sunspots and found that the surface of the moon was covered in craters and peaks. Galileo also created a heliocentric model of the universe.

Kepler: 1571 CE - 1630 CE Johan Kepler created the three laws of planetary motion that are still true to this day. He also was able to explain that Mars occasionally appeared to move backwards through explaining that orbits are elliptical.

Newton: 1643 CE - 1727 CE Isaac Newton created the universal law of gravitation that states that all matter has some gravitational pull. He was the first person to show that astronomical and earthly forces are the same.