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322 BCE
Aristotle
He thought earth was center of universe. He also thought the planets around earth were spherical. Thought moon,sun, and planets were attached to invisible shells orbiting earth. -
120 BCE
Hipparchus
Wrote first star catalog. Calculated distance from earth to moon. -
170
Ptolemy
He had tolemy geocentric theory. -
1543
Copernicus
He formulated a model of universe to show his believe heliocentric/ sun in middle of universe.ritish Inventor of scientific steps. -
Tycho Brahe
He devised the most precise instruments before telescopes. -
Hans Lippershey
Invented the telescope. 3x magnification. -
Johannes kepler
Tycho brahe’s assistant. Discovered that the orbit of the planets are not circular but elliptical. -
Galileo
He discovered the mountains on the moon the spots on sun and the four moons to jupiter. These helped the theory that the earth revolves around the sun. Io Europa Ganymede and Callisto. -
Giovanni Cassini
Discovered Saturn 4 moons and determined distance between earth and mars. -
Sir Isaac newton
invented reflecting telescope. -
William herschel
found uranus and its two moons and founder of sidereal. Also founder of refraction. -
Percival Lowell
Predicted existence of a planet beyond orbit of neptune and initiative the search that ended in discovery of pluto. -
Karl jansky
Discovered radio waves. -
Edwin Hubble
He discovered the universe is expanding. -
Albert Einstein
Theory Relativity and gravitation. -
Sputnik
First satellite To orbit space. -
Yuri Gagarin
First person to ever orbit earth -
John glenn
First American to orbit earth -
Ejnar Hertzsprung
Discovered Brightness and the spectral type of star. -
Neil armstrong
First person to walk on moon. -
Apollo Program
Sent tesla to space. -
Mars pathfinder expedition
American Robot Roaming on mars -
Cassini orbiter
Went to saturn. Took 30 years.