For as long as I can remember I have been absolutely fascinated by the science of astronomy. This year I am in for a special treat as 2009 has been designated the International Year of Astronomy.
The possibilities are endless!
What is Astronomy? Astronomy is the study of the space beyond the earth, as well as happenings within the earth’s upper atmosphere which have their origins in space (these include aurora and meteors). Astronomers study the motions of celestial bodies such as the planets, stars and galaxies, the chemical make up of these bodies and their physical structure. Astronomy draws on many different fields of science such as mathematics, chemistry, geology, physics and biology.
Astronomy is one of the oldest forms of science practiced by people, our ancestors have been looking into the skies and trying to make sense of what they saw there for as long as there have been people. By understanding the motions of the planets, early astronomers could correctly determine the best times to plant and harvest crops. Many celebrations were dependent on a particular phase of the moon or the position of a specific planet (literally “wandering star”).
The man known as the “father of modern observational astronomy” (amongst other sciences which he revolutionised) is Galileo Galilei. On 25 August 1609 Galileo demonstrated his first telescope to Venetian lawmakers. He had expanded on the work of Hans Lippershey of the Netherlands and created the first instruments which could magnify ground and space based objects by a magnitude of 30 times. This revolutionary step forward allowed Galileo to observe Venus’ phases (like our moon) and he discovered that four moons traveled around Jupiter. He then realised that the Ptolemaic theory (that the earth was the center of the universe and all heavenly bodies, including the sun, revolved around us) which had been accepted up until then was wrong. The image at right is taken from Galileo’s manuscripts and it shows where he first recorded his observation of moons orbiting Jupiter.
We have come a long way since Galileo’s amazing discovery and our understanding of the workings of the universe are far better developed. It is through astronomy that we are able to grasp how we fit into the universe. Four hundred years ago it was believed that the universe and everything within it was created for us, now we are able to appreciate just how insignificant we are in the grand scale of the cosmos. Here is an amazing video which illustrates the size of our planet compared to other celestial bodies.
As Carl Sagan, the great teacher, once said;
Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies then people.
Not only does astronomy allow us to learn a great deal about the world around us, it also boasts some of the most incredible beautiful things to look at. The Hubble Space Telescope (HST) was launched into orbit around earth in April of 1990 and it has enabled us to see galaxies as far as 13 billion light years away. Wikipedia has an excellent article on the Deep Field image taken by the HST in December of 1995.
During this year I will post regular articles about new discoveries in astronomy, I will also highlight interesting objects which are easy to see in the night sky (from South Africa) and I will occasionally post links to gorgeous photos. Stay tuned!