The Golden Age of Astronomy
17 December, 2007
The universe is unimaginably big. The closest stars to our own sun are so far away that it takes years for their light to reach us, and light travels pretty darned fast. The constellation Orion is one of the most recognisable in the night sky. This constellation leads us to three stars, and backwards through time.
The bottom right star of Orion, the ‘foot’ if you like, is called Rigel. The light you see when you look at Rigel left that star system approximately 800 years ago. Back then astronomy was really still astrology. Like the Magi of Babylon, astronomers in those days looked at the sky and tried to predict the future. Seasons, eclipses and the death of kings were looked for in the stars. The geocentric model of the solar system still held sway, everyone thought that the Sun went around the Earth.
Betelgeuse sits at the top left of the constellation Orion. It is noticeably red, a bloated giant ready to become a supernova, on the edge of death and destruction. The light we see left it about 400 years ago. Around then Galileo was looking through his telescope, seeing for the first time mountains on the moon, the phases of Venus, and the moons of Jupiter. The Sun was recognised as the true centre of the solar system as the evidence of these observations came in.
Sirius follows Orion as they rise. To the ancient Egyptians, Sirius was Isis, who followed her husband Osiris (Orion) into the sky and whose appearance in the night sky heralded the flooding of the Nile. It is one of the closest stars to us, the brightest in the night sky, and it’s light started the journey through space just 8 years before reaching the Earth. In these past 8 years there have been more discoveries in astronomy than in any other 8 year period. Advances in digital technology have allowed amateur astronomers to contribute to professional research. The giant space telescopes continue to give finer resolution over larger ranges of the electromagnetic spectrum, allowing us to see more of the universe. The Sloan Digital Sky Survey watches the skies and then gives the images to the world over the internet allowing teams to make discoveries by trawling the vast amounts of data it has collected.
In the last few years astronomers have seen evidence of dark matter, of an ever expanding universe, of super massive black holes. We have mapped the cosmic background radiation and found it matched the predictions of the big bang theory exactly. We have seen a solar eclipse where Saturn is the object between the camera and the sun. Dwarf planets larger than Pluto have been found in our solar system. Hundreds of extra solar planets have been found around nearby stars. We are living in the golden age of astronomy.