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Period: 100 BCE to 170 BCE
Ptolemy
Though his ideas were flawed, they served as a launch-pad for later, more accurate ideas. His theory that the sun and the planets spin in their own orbit while orbiting the Earth was obviously false, but later on, other astronomers were able to use it to understand the truth. -
Period: 1 BCE to 127 BCE
Hipparchus
Not much is known about him, but what we do know is that he laid the foundations of trigonometry, and discovered the precession of equinoxes. He was also able to calculate the length of a year by just a few minutes. -
Period: Feb 19, 1473 to 1543
Nicolaus Copernicus
Known as the father of modern astronomy, he was the first to pitch the idea that the Earth and other planets revolve around the sun. He also was able to accurately predict the orbital periods of all the known planets. -
Period: Dec 14, 1546 to
Tycho Brahe
He was famous for accurately predicting the positions of over 700 stars. he was the first to observe a supernova in the constellation Cassiopeia. He died poor and unrecognized. -
Period: Feb 15, 1564 to
Galileo Galilei
Galileo Galilei figured out how to make a telescope, improved the design, and used it to discover the four biggest moons of Jupiter and the rings of Saturn. He also charted the moons phases and discovered that it is not smooth. -
Period: Dec 27, 1571 to
Johannes Kepler
Kepler was extremely important to science because he devised the three laws of planetary motion: all planets move in an elliptical orbit, a planet covers an equal distance in an equal amount of time in relation to the sun, and a planet's orbit is in direct correlation with the time it takes to complete a full revolution. Kepler was a huge inspiration for Isaac Newton. -
Period: to
Isaac Newton
This man was incredibly important to science, because he divised the laws of gravity which we can see every day. He also discovered the laws of planetary motion, which are still used in charting mission courses and understanding space today. -
Period: to
Edmond Halley
He recorded a transit of Mercury across the Sun, and charted the course of the comet which was later named after him and won't return again until 2061. -
Period: to
Charles Messier
He discovered over 100 different nebulae, star clusters, and distant galaxies, and published a catalog stating their existence. These objects were later generalized into a group known as the Messier objects. -
Period: to
Edwin Powell Hubble
He was incredibly important to astronomy, as he provided evidence for an expanding universe, and created a way to classify galaxies. The Hubble Space Telescope was named after him.