Hipparchus of Rhodes

Hipparchus of Rhodes or Hipparchus of Nicaea (190-120 BC) was a Greek astronomer, geographer, cartographer and mathematician. People call him “the father of astronomy”.

In the 2nd century BC he calculated that the solar year is 365.242 days.

In 143 BC Hipparchus set the basis of Astronomy because he claimed that the stars aren’t eternal on the sky.

Hipparchus has invented the astrolabe.

He perfected the Dioptra

and other older instruments like the hourglass

the links (rings)

the solid ball and the sundial

He was also the first person who made the terrestrial globe.

In 2006 a research team announced that a group of toothed wheels inside the mechanism represented the moon’s speed. They believe that Hipparchus was involved with the construction of that instrument.

Finally, he created the first star catalogue, which unfrotunately has been lost.

Jenny Kipourgou, Grade 2, Level 2, 2nd Junior High School of Paralia







Aristarhos from Samos

Aristarhos was born in 310 BC and died in 230 BC. He was a Greek astronomer and a Maths teacher. He was born in Samos.

He suggested that the sun was the centre of the solar system. Originally, his ideas about astronomy were not accepted. He observed the movement of the moon and claimed that the diameter of the Earth was three times bigger than the diameter of the moon. He reached the conclusion that the sun had a diameter twenty times bigger than that of the moon and that the sun is bigger than the Earth.

Τηλεσκόπιο 'Αρίσταρχος' στα Καλάβρυτα.

In the picture above you can see “Aristarhos”, the second biggest telescope in Europe named after  this great Greek astronomer, and which is on the mountain in Kalavryta, a town about 80 kms away from Patra.

Demetres Proskefalas, Grade 2, Level 2, 2nd Junior High School of  Paralia









Andronicus of Cyrrhus

Andronicus of Cyrrhus was an ancient Greek engineer. He was from Cyrrhus . He was Hermia’s son.

He made the sundial from white marble, the celestial globes and other astronomic instruments.

He also built a clock in Athens, which is known as the Tower of Winds and you can see it even today.

The Tower of Winds.

Panayiotis Kanelakopoulos, Grade 2, Level2, 2nd Junior High School of Paralia.