5.8 Astronomers

Eratosthenes

240 BCE

Eratosthenes is famous for calculating the circumference of Earth. This was huge to astronomy because it was one of the first huge successes in scientific calculation.

Claudius Ptolemy

150

Claudius Ptolemy is known for his geocentric model of the universe. Although this model is not accurate, it allowed astronomers to make predictions about planetary positions.

Nicolaus Copernicus

1543

Nicolaus Copernicus is known for developing Copernican heliocentrism. This was important to astronomy because it placed the sun at the center of the solar system instead of Earth. At the time this was a new idea, and we now know that it is true.

Tycho Brahe

1583

Known for creating a model of the solar system called the Tychonic System. This model was important to astronomy because it included the sun revolving around the Earth (geo-heliocentric model).

Johannes Kepler

1609

Johannes Kepler discovered that the orbit of Mars is in ellipse. This is what led to the two laws of planetary motion.

Sir Isaac Newton

1687

Sir Isaac Newton is well known for discovering the 3 laws of motion. These laws are the foundation of mechanics, and they give us a lot of information about the universe around us.

Albert Einstein

1915

Albert Einstein was one of the most influential scientists of all time. One of his most famous developments in astronomy was the theory of relativity. This theory is important because it changed the human understanding of space, time, and gravity.