An Introduction to Astronomy
What is Astrology ?
Astronomy is derived from the Greek astronomos
nomos = a system of laws
Today “Astronomy” is synonymous with “Astrophysics“, the study of the physics of celestial objects; the solar system and its consituents, the properties, birth, life and death of stars, interstellar gas and dust, galaxies and clusters of galaxies, and finally the study of the Universe as a whole (“Cosmology“).
Definition of astronomy :
Astronomy is the study of the sun, moon, stars, planets, comets, gas, galaxies, gas, dust and other non-Earthly bodies and phenomena.
NASA defines astronomy as simple “the study of stars, planets and space.”
How did Astronomy start?
During the renaissance period , astronomy began to undergo a revolution in thought known as the Copernican revolution, which gets the name from the astronomer Nicolaus Copernicus, who proposed a heliocentric system, in which the planets revolved around the Sun and not the Earth.
Astronomy is the oldest of the natural sciences, dating back to antiquity, with its origins in the religious, mythological, cosmological, calendrical, and astrological beliefs and practices of prehistory: vestiges of these are still found in astrology, a discipline long interwoven with public and governmental astronomy.
It was not completely separated in Europe (see astrology and astronomy) during the Copernican Revolution starting in 1543.
In some cultures, astronomical data was used for astrological prognostication.
Ancient astronomers were able to differentiate between stars and planets, as stars remain relatively fixed over the centuries while planets will move an appreciable amount during a comparatively short time.
The Nebra sky disc is a Bronze Age bronze disc that was buried in Germany, not far from the Goseck circle, around 1600 BC.
It measures about 30 cm diameter with a mass of 2.2 kg and displays a blue-green patina (from oxidization) inlaid with gold symbols.
Found by archeological thieves in 1999 and recovered in Switzerland in 2002, it was soon recognized as a spectacular discovery, among the most important of the 20th century Investigations revealed that the object had been in use around 400 years before burial (2000 BC), but that its use had been forgotten by the time of burial.
The inlaid gold depicted the full moon, a crescent moon about 4 or 5 days old, and the Pleiades star cluster in a specific arrangement forming the earliest known depiction of celestial phenomena.
Twelve lunar months pass in 354 days, requiring a calendar to insert a leap month every two or three years in order to keep synchronized with the solar year’s seasons (making it lunisolar).
The earliest known descriptions of this coordination were recorded by the Babylonians in 6th or 7th centuries BC, over one thousand years later.
Those descriptions verified ancient knowledge of the Nebra sky disc’s celestial depiction as the precise arrangement needed to judge when to insert the intercalary month into a lunisolar calendar, making it an astronomical clock for regulating such a calendar a thousand or more years before any other known method.