Melc 2

• The most observable celestial objects in the sky are Stars, sun and moon.
• Babylonian and Egyptian used a traditional version of sundial, called Gnomon sistematically observing the motion of sun.
• sun rises in East and sets in west.
• They also recorded that the points where the sun rises and sets on the horizon differ over a year and those changes happen seasonally.
• Babylonian astronomers developed zodiac sign. •Shy is divided into 3 sets of 30° and the group of stars that inhabit each sector.
• Constellation Schemes. use for predicting and setting of the planets, and lengths of daylight as measured by water clocks.
• Lunar Eclipse- occurs when the Earth is in between the sun and the moon/ when the moon moves into the Earth's shadow.
• Aristotle made 3 important observations or arguments Ships dissapeared as it pass through horizon. Travelers going south observed that southern constellations lies above the horizon. During Lunar eclipse, the Earth's shadow is circular/ round shape.
• Pythagoras and Plato taught students that the world was round / spherical but they have no exidence to show.
• Greeks traveled near equator, they noticed that Northern star is seem closer to the horizon
• Visibility of Planets - Astronomers discovered that Mercury, Venus, Mars, Jupiter, and saturn were classified as planets because they have noticed that the stars are in a fixed position with respect to each other. Bright stars changed positions periodically. ↳ They do not belong to any group of stars in the stay. - There cosmic bodies are called "wanderers" or planetes in Greek Terms.
• Motion of the stars > stars appears to be attached to a celestial phaser sphere that rotates around an axis in a day. → The axis of the northern sky closely intecepts with the northern star known as Polaris. constellations positions in the night sky changes depending on the time of the year.