Ancient Astronomer's

Eratosthenes of Cyrene

240 BCE

Born: 276 BC
Died: 194 BC
Discovery: Accurately measured the circumference of the Earth
Importance: It was important because it allowed us to determine the shape and size of the earth.

Claudius Ptolemy

140

Born: 100 AD
Died: 160 AD
Discovery: Geocentric Model
Importance: This explained that the earth was at the centre, and all planets and the sun orbited around it.

Nicolaus Copernicus

1532

Born: February 19, 1473
Died: May 21, 1543
Discovery: Heliocentric Solar System
Importance:A system in which the planets and planetary objects orbit the sun. Nicolaus Copernicus theory regarding earth's place in the universe greatly contributed to the start of the Scientific Revolution.

Tycho Brahe

1583

Born: December 14, 1546
Died: October 24, 1601
Discovery: Tychonic System
Importance: At the time, people believed in a geocentric model of the universe with the earth at the center. Tycho Brahe helped overturn that belief in favor of a heliocentric model of the universe, with the sun at the center. Tycho Brahe's legacy is that he left a lot of astronomical data for other scientist to use.

Johannes Kepler

1609

Born: December 27, 1571
Died: November 15, 1630
Discovery: Three major laws of planetary motion
Importance: This was important because it determined how planets traveled around the sun in elliptical orbits.

Sir Isaac Newton

1686

Born: January 4, 1643
Died: March 31, 1727
Discovery: Developed the three laws of motion which form the basic principles of modern physics.
Importance: It governs the behavior of everything that is seen and unseen on Earth and in the cosmos, from the trajectory of a baseball to the motion of a planet.

Albert Einstein

1915

Born: March 14, 1879
Died: April 18, 1955
Discovery: Theory of Relativity
Importance: The theory of Relativity was important because it foreshadowed the development of atomic power and the atomic bomb.