What is astronomy?

What is astronomy? When did it 

begin? Astronomy is a study of virtually 

everything beyond earth. The academic 

discipline includes studying planets, solar 

systems, stars, galaxies, comets, asteroids, 

nebulae, moons and the Universe itself. You 

will learn about these fields of study as you 

read this book. 

Astronomy has produced a relatively 

new field: astrobiology. So far, this 

scientific endeavor only speculates about 

possible alien life. But, as you will study in 

this book, there are possibilities of alien life 

even inside our solar system. Part of the 

astronomical science community is actively 

listening for new signs of life in the cosmos

(Another word for universe.). This 

organization is called the SETI Institute. 

The abbreviation stands for: Search for 

Extra Terrestrial Intelligence. 

A very active part of astronomy 

consists of teams of astronomers looking for 

exoplanets. These exoplanets are circling 

stars outside our solar system. Literally 

hundreds of these planets have been found. 

Several new ones are discovered every 

month. 

Many new discoveries that have 

been made over the last 40 years have been 

heavily computer dependent. Modern 

astronomy relies upon technology, math and 

scientific method.

Skills and To o ls o f 

the trade 

Astronomy is a visually - based 

science. The skill of careful observation is 

essential to understanding and discovery. 

Many astronomical skills were developed as

long as 5,000 years ago. Before written 

history began, people had noticed the

interrelationships between the Sun, Moon 

and the Earth. Observations resulted in a 

rudimentary understanding of the timing of 

days, nights, monthly patterns of moonlit

shapes and the seasons. Missing were 

scientific reasons for these events. When 

there were no answers for natural 

occurrences, observers concluded that it was 

caused by actions of the gods. 

Astrology and its astrologers were 

cosmos based, religious fortune tellers and

“the gods’ will”, messengers. They closely 

studied the stars, planets, the moon and sun 

and then tried to derive meaning for their 

movements. At times important decisions 

(war, marriages, coronations, etc.), were 

timed because of predictions put forth by 

these astrologers. 

Some of their observations were 

quite helpful. They could advise when to 

plant and harvest. They could determine 

when the next full moon night would occur. 

For those who lived near coasts, they could 

predict tides. They learned to use star 

patterns for day and night time navigation.