Why we have the Centaur, the Phoenix and the Furnace in the night sky

All over the world, different races and cultures have impressed their myths on the stars.

Heroes and objects from mythology are there in the sky as groupings of stars, called "constellations".

One common factor is very few of these constellations resemble even remotely what they represent. Cassiopeia looks like a "W", although the constellation represents a queen sitting on a throne. Her husband, Cepheus, has a constellation that actually looks like a house. Picking one's way around the sky, identifying the constellations is one of the challenges facing beginners in astronomy.

Today, both professional and amateur astronomers have telescopes where one just dials in the object to be observed, and the telescope automatically points at it. One does not have to know the constellations, but knowing them is part of enjoying the night sky.

Those heroes, animals, ships and other objects set out among the stars come from thousands of years of our culture, with roots among the Arabs and the ancient Greeks. Many of our constellations were first listed by Ptolemy, a Greek astronomer, around 1,800 years ago.

Here in North America, Indigenous peoples looked at the skies too, and over thousands of years wrote their stories among the stars. One thing we all have in common is we all wrote about our cultures in the sky.

Over the centuries there have been attempts to update or "rationalize" the constellations. One proposal was to name the constellations after “important” politicians, no doubt with the politicians telling us who the important ones would be.

Getting a world-wide consensus about which politicians to put in the sky would be more than a challenge. Fortunately, we have all agreed the naming of things in the sky will remain the responsibility of the International Astronomical Union (IAU).

Names for newly discovered objects are proposed to the IAU. That organization vets them for acceptability among all the participating nations. For the constellations visible to the civilizations of the Northern Hemisphere, the names are well established, and we all like the Greek legends. However, a challenge came up when, in the 16th Century, European astronomers ventured into the Southern Hemisphere for the first time, and saw stars they had never seen before.

Today, our approach would probably be to ask the people already living in the Southern Hemisphere about their constellations. However, back in the 16th Century, the explorers followed their own ideas for setting up new star groupings to fill in the blanks.

Some of these new constellations followed the myth-based system used in the Northern Hemisphere, giving us, for example, Centaurus (The Centaur) and Phoenix. Others were named after birds, such as Tucana (The Toucan), Pavo (The Peacock), Grus (the Crane) and Columba (the Dove). Laboratory equipment followed, such as Microscopium, Telescopium, Fornax (The Furnace), Octans (The Octant), Antlia (The Air Pump), and so on. For some reason, there is Musca (The Fly). Was this an Australian contribution? Then there is Mensa (The Table), named after Table Mountain in South Africa.

One constellation, called Argo Navis, was named after Jason's ship, the Argo, which carried him on his quest to find the Golden Fleece. This constellation was eventually deemed too big, and broken up into a number of smaller ones—Vela (the Sails), Puppis (the Stern), and Carina (the Keel). Then of course there was the Southern Cross, the one southern constellation we have all heard of.

There are proposals to review some of the constellations, particularly those in the southern half of the sky. Fortunately the IAU is there to ensure they will receive extensive discussion first.

Most astronomers like things the way they are.

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• After sunset, Jupiter lies in the south-east and Saturn in the south, with Mars rising in the east.

• The Moon will be full on the Dec. 7.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.