Knowing Space: A Short History of Astronomy

Astronomy is essentially the study of space – the universe and all the celestial bodies that make up our galaxy, including their structure and history. It means pointing our sights towards the sky and making observations about space.

Astronomy as a science is considered the oldest. It dates back to the time when people began looking at space and observing how everything in it behaved. They soon came to the conclusion that there was a certain predictability to the movements of the stars and planets. Ancient peoples then began to use this knowledge to tell time.

Astronomy and Time
Our modern use of clocks and other time measuring devices owe a lot to astronomy and the study of space. People during the ancient times used the movements of the sun, moon and other stars to tell time and set the seasons for human activities such as planting and harvesting.

Even early celebrations pertaining to religion was based on the movements of celestial bodies in space. The early form of astronomy was a great help in establishing regularity and measurable time, especially when used with man-made implements.

A famous example of this is the Stonehenge, a massive stone structure that was used as an observatory as far back as 3000 BC. It mainly tracked the sun's movement along the horizon to predict the coming and going of the seasons. About 500 years later, Stonehenge may also have been utilized to predict lunar eclipses as well.

By 1800 BC, the early Babylonians were able to develop a rough calendar based on the Sun's movement and the moon's phases. Models of the supposed circular motions of the celestial bodies in space were developed by the Greeks and were later on enhanced by Hipparchus and Ptolemy. Johannes Kepler later replaced the circle with the ellipse.

Other famous astronomers who made major contributions to our modern knowledge of space include Nicolaus Copernicus and Galileo Galilei. Copernicus refuted Ptolemy's theory of an earth-centered galaxy and instead theorized that the sun was the center around which the planets revolved.

Galileo Galilei improved on this further when he used a telescope to explore space in 1609. Although he was tried by ecclesiastical authorities for his theories, Galileo's insights were proven correct later on.

Astronomy today
Astronomy has a few practical uses, but it is engaged in by many professional and amateur astronomers because it does satisfy our thirst for knowledge of space. Today, various methods are used in exploring space, including radio, infrared, x-ray, ultraviolet and gamma-ray astronomy.

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