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big bang
it hapened 13.8 billions of years ago and creats our universe. -
Aristarchus of Samos
suggested that the Earth revolved around the sun. -
Hiparchus
the greek astronomer that cassified the stars according to their apparent brightness. -
Ptolomy
suggested a geocentric astronomic model. According to him,the sun , the moon and the five known planets (mercury,Venus,Mars,Jupiter and saturn) all revolved around the Earth. -
Copernicus
Published his heliocentric model -
Tyco Brahe
carried out very detailed observation of the planets. -
Galileo
used a telescope r the first time to observe the night sky -
Isaac Newton
built the first telescope using mirrors instead of lenses. -
Newton book
the principles of natural philosophy in wich he explained the laws governing the movement of planets. -
Edmund Halley
explain Newton's laws annd predicted the return of the comet -
F.W. Bessel
measured the distance from a star for the first time using geometric methods. -
The work carried by Adams,Galle and Leverrier
descover neptune. -
E.P. Hubble
proved that someone of the nebulas seen in the sky are in fact independent galaxies. -
Tombough
discover the planet Pluto -
1995
the discover of the first extra-solar planet
