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Period: 276 BCE to 195 BCE
Eratosthenes
A Greek mathematician, astronomer, and geographer. He used the sun to measure the size of Earth, finding that it was 24,660 miles (211 miles off true measurement). This was important since this had not successfully been done and documented before. -
Period: 90 to 168
Claudius Ptolemy
An astronomer and mathematician in ancient Greece. He set up a model of our solar system in which everything revolved around the Earth. This was later proven wrong but layed groundwork for other astronomers to build off of and find out the real format of our solar system. -
Period: 1473 to 1543
Nicolaus Copernicus
An astronomer in Poland who introduced the idea of the Earth revolving around the Sun instead of the other way around. This helped astronomers with looking at Mars' path, since it made little sense at the time, and helped Galileo's assertions that the Earth orbited the Sun. -
Period: 1546 to
Tycho Brahe
An astronomer from a Danish noble family, who created his own idea of how the solar system was set up, with the other planets orbiting the sun which orbited the Earth. Although his idea was proven wrong, he managed to also achieve measuring to one minute of arc. This finding helped future astronomers with measurements in our solar system. -
Period: 1571 to
Johannes Kepler
A Greek astronomer who worked with Tycho Brahe, and found that the planets orbited the sun not in circles but in ellipses. This was because of help from Brahe and his idea for Kepler to study Mars' orbit. Kepler's finding was made into a law, along with three others that helped shape astronomy for future astronomers. -
Period: to
Sir Isaac Newton
An English astronomer who specialized in studying gravity. He built on the works of people from before him and founded rules for gravity. With his discoveries with gravity, later astronomers were able to use his ideas to further their own research. -
Period: to
Albert Einstein
A German physicist who proposed a new way of looking at the universe, by proposing that the speed of light in a vacuum is constant, and that space and time are linked in an entity known as space-time which is distorted by gravity. This idea helped future astronomers when it came to measuring the solar system.