Ancient Astronomers

Eratosthenes

194 BCE

The father of Geometry used geometry to calculate the circumference of Earth. This helped navigation in ancient times.

Claudius Ptolemy

150

created Ptolemaic System This was a model of our solar system with Earth being the center. Scientists followed this theory for 1,200 years.

Tycho Brahe

1572

observed a super nova and a comet. He proved that the Super Nova did not change compared to the surrounding stars. He also noted the comet orbited behind the moon. This discovery differed with the idea that the heavens never changed. This is called the Tychonic system

Johannes Kepler

1609

used research of the heavens that Tycho Brahe compiled to prove the planets orbits were ellipses. This became Kepler's 3 laws We use this today to understand the orbits of the planets. He published Astronomia Nova.

Nicolaus Copernicus

1632

said the earth revolved around the Sun. Copernicus Revolution this changed how scientists understood the structure of our solar system.

Sir Isac Newton

1687

published writing stating the law of motion. "For every action, there is an equal and opposite reaction." part of his laws of motion included our understanding of gravity which we see every day in our lives as well as our solar system.

Albert Einstein

1687

discovered the laws of physics is constant throughout the universe. He stated light speed is constant inside of a vacuum, and space-time is changed by gravity. This discovery helped scientists understand the movement of the objects in space.