The Great Bear


The Big Dipper needs no introduction – yet it crossed my mind, this celestial constant might deserve a little ponder. Often mistaken for a constellation, the seven stars – Alkaid, Mizar, Alioth, Megrez, Phecda, Merak and Dubhe – form an Asterism, or subset of stars within a constellation. in this case Ursa Major – the Great Bear.

In November, the Great Bear descends to the lowest point along northern hemisphere horizons. Micmac people of southeast Canada saw this as a sign “earthly” bears went into hibernation, and tree sap returned to the “womb of creation”. Ursa Major appears to touch the earth, winter takes full command. The great bear sleeps, her extremities falling below the horizon yet the Big Dipper manages to hover above the edge of perception.

The Big Dipper doesn’t come and go with seasons, it’s circumpolar, meaning it lies in the same direction as the celestial north pole.  A line drawn outwards from the pole would pass  practically through the Dipper, and intersect with Polaris (the North Star). Earth rotates on its axis around Polaris, stars that are circumpolar to the north pole travel in tight circles around Polaris, therefore visible all year, albeit with a few sways and dips. If the Big Dipper was a clock moving once around Polaris every 24 hours –  the “bowl” would always face Polaris – at 6 o’clock it would appear flat, 3 o’clock standing on the handle, 12 0’clock upside down, and 9 o’clock standing on the bowl.

Lay eyes on the Big Dipper, finding Polaris becomes a simple matter of locating the two outermost stars of the bowl (farthest from the handle) – draw an imaginary line up and beyond for roughly 5 times the depth of the bowl – voila, the North Star.

Think of the Big Dipper as a celestial guide – take comfort in understanding it will never allow you to loose your way. If you see it, you can find north. You don’t need to panic if your GPS craps out – celestial navigation won’t let you down.

http://www.theskyscrapers.org/getting-to-know-the-big-dipper

Image Credit: AlltheSky.com

09nov12_430

Advertisements

Polaris Dippers


Asking people to “look at the damn sky” isn’t much good if they don’t know what they’re looking at. It’s easy to assume everyone can find the big dipper or locate the North Star. In the spirit of “baby steps” – everything you ever needed to know about finding the “dippers” and locating Polaris, the North Star.

The Big Dipper is always found in the north sky – in spring and summer, high in the sky – fall and winter, close to the horizon. Made up of seven stars forming a bowl and handle, the two outside stars of the bowl are Dubhe and Marek –   the “pointer stars” leading to Polaris and the Little Dipper.  Follow them in a straight line and Polaris is always there – a cosmic anchor for “dippers”  making a complete circle of the north star every 23 hours and 56 minutes.

No matter what time of year you look, the two outer stars in the Big Dipper’s bowl always point to Polaris.

http://earthsky.org/favorite-star-patterns/big-and-little-dippers-highlight-northern-sky?utm_source=EarthSky+News&utm_campaign=0a997ec4e9-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-0a997ec4e9-393970565

Polaris may not be the brightest star in the sky – ranking 50th is inconsequential to a stellar constant above the “celestial north pole”. A star of many names; pole, north, steadfast, lodestar, guiding; a fixed point in the sky responsible for navigation of the ancient world. A gift of cosmic confidence powerful enough to sail into the unknown, the only GPS northern hemisphere travellers needed to find their way home. A beacon of hope for American slaves heading north to freedom – and once you know how to find it, a way back to the car when you’re lost in the woods.