Aristotle

Aristotle

322 BCE

Aristotle-(384-322 B.C )He proved the earth is round.He also thought that stars traveled in separate spheres.He also believed the sun was the center of the universe.

Ptolemy

170 BCE

Ptolemy-(100-170 A.D)He believed the earth was the center of the earth.He thought that the earth moved along a equant.He tried to predict stars movements.

Hipparchus

120 BCE

Hipparchus-(190-120 B.C)He is founder of trigonometry.He calculated the length of a year created the first catalog of the stars.

Copernicus

1543

Copernicus-( 1473-1543)He had another theory that the planets revolved around the sun.Although the model he made to represent it wasn't completely right, it built a strong foundation for future scientists to build off of.

Tycho brahe

1601

Tycho Brahe-(1546-1601)He made precise instruments before the telescope was invented.With his inventions he was able to track planet motions.

Hans Lippershey

1619

Hans Lippershey-(1570-1619)He is believed to be the one to make the first telescope and the first sketches of the telescope.He was a lense maker.

Johannes Kepler

1630

Johannes Kepler-(1571-1630)He was a German astronomer who discovered (1) the planets move in elliptical orbits with the Sun at one focus; (2) the time necessary to traverse any arc of a planetary orbit is proportional to the area of the sector between the central body and that arc (the “area law”); and (3) there is an exact relationship between the squares of the planets’ periodic times and the cubes of the radii of their orbits (the “harmonic law”).

Galileo

1642

Galileo-(1564-1642)He made improvements to the telescope.The improvements he made where improving the lense magnification on the telescope.He also made the first studies of the planet neptune

Mariners Astrolabe

1981

The mariner's astrolabe, also called sea astrolabe, was an inclinometer used to determine the latitude of a ship at sea by measuring the sun's noon altitude (declination) or the meridian altitude of a star of known declination.