Many people learned about the Big Dipper when they were children. Perhaps a parent pointed it out, or it was in school or at a planetarium show.  Lesser known is the Little Dipper.

Are they constellations? No. They are asterisms which are star patterns.  These Dippers are part of the constellations of the Big Bear and Little Bear (Ursa Major and Minor).

In all my years of stargazing, I still can only see those constellation shapes on a chart or planetarium show when someone connects the dots – and even then it is a stretch of the imagination!

But the shape of a dipper (once used to get a drink of water from a larger vessel or well) is pretty easy to see. This month you can find the Big Dipper high in the northern sky. The two outer stars in its bowl are referred to as pointer stars because they point to the North Star (Polaris) which is the end of the Little Dipper’s handle.

In Star Names: Their Lore and Meaning, it says that the ancient Greek writers (like Homer) didn’t mention Ursa Minor or the dipper shape.  I always marveled at seeing the stars and planets as a child thinking that I am looking at the same sky that ancient people saw.

This group of stars became the “wings” of the constellation Draco the Dragon. When, around 600 B.C., the Phoenicians showed the Greek philosopher Thales how to navigate by the stars, he supposedly used the Dragon’s wings to create a new constellation. This might have been to make it easier to show them how to locate the north celestial pole.

Ursa Minor was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. The Bears’ tails are the dippers’ handles.

Further falling away of my childhood star knowledge came when I learned that our Polaris,  which marks the north celestial pole in the sky, was not the star those ancients would have used to navigate. Kochab and Pherkad at the end of the Little Dipper were closer to the north celestial pole in 600 B.C.

Learning how our sky view of the heavens has changed over the centuries isn’t at all disappointing to me, but rather a reminder that everything is changing.

chart

The Liitle Bear with The Dragon looping around it, as depicted in Urania’s Mirror, a set of constellation cards published in London c.1825

 

UrsaMinorCC.jpgUrsaMinorCC” by Till CrednerOwn work: AlltheSky.com.
Licensed under CC BY-SA 3.0 via Wikimedia Commons.

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