For those of us who live in large towns and cities, it is easy to forget the beauty of the night sky. Seldom do we travel far from the bright lights and out into the country to see the stars in all their grandeur. Haze and bright lights didn't handicap our distant ancestors, however.

They could see the sky on any clear night from wherever they were. Pictures in magazines, newspapers, movies or television didn't weaken their imaginations. They told stories filled with imagination, using patterns of stars for illustrations. These patterns -- the constellations and other star groupings -- are the legacy of their imaginations.

The fact that the Big Dipper, now nearly overhead for most northern observers during the mid-to-late evening hours, formed a bear to American Indians and to cultures of the Old World and Siberia suggests that Ursa Major, as it is called today, is a star pattern recognized in ancient times.

Long ago, when the forms of animals and heroes were pictured against the stars, a large bear was represented in this particular region, a bear with a surprisingly long tail (because the Dipper has a long handle).

It is a piece of Stone Age culture thought to be at least 8,000 to 12,000 years old. That is the estimated era of the last migration from Siberia to North America across the Bering Strait. And the far-northern region of the world, where this starry figure wheels high in the heavens, came to be known as the Arctic region -- the abode of Arktos, which in Greek literally meant bearish.

The Big Dipper itself has been a source of frustration to some constellation historians. Who exactly originated this name? For much of the world this pattern has been, if not a bear, then some sort of wagon.

In Ireland, for instance, it was recognized as "King David's Chariot," from one of that island's early kings; in France, it was the "Great Chariot." Another popular name was Charles's Wain (a wain being a large open farm wagon). In the British Isles, however, these seven stars are known widely as "The Plough."

But as a long-handled pot or ladle it is strictly an American phenomenon, first mentioned in 19th Century astronomy books, but apparently not before then.

A very convincing tin dipper it is, with its handle bent downward.

Incidentally, it is wrong to refer to the Big Dipper as a constellation. There are 88 groups of stars that are officially recognized and listed as constellations. The Big Dipper, famous as it is, has no official status and is only recognized as being a conspicuous part of a constellation (Ursa Major).

Such a star pattern is called an asterism.

For many sky gazers, the Big Dipper is the most important group of stars in the sky. For anyone in the latitude of New York (41 North) or locations northward, it never goes below the horizon. It is one of the most recognizable patterns in the sky and thus one of the easiest for the novice to find.

Of greatest importance is the ability to utilize the Big Dipper to locate Polaris, the North Star.

This is made possible by the two bright stars that mark the outer edge of the bowl of the Big Dipper. These two stars - Dubhe and Merak - are known as the Pointers, because they always point to Polaris. Just draw a line, in your imagination, between these two stars and prolong this line about 5 times, until you hit a moderately bright star. That will be Polaris. [See map at the top-right of this page.]

Close to the middle star of the handle, Mizar, sits a tiny star, Alcor. These two stars are not physically connected but are in the same line of sight from the Earth. Consequently, they appear inseparable, and visually they are, except to a person with perfect eyesight. They appear to be separated by just 12 arc minutes, or two-tenths of one degree. That's less than half the apparent width of the Moon.

Before the age of eyeglasses and oculists' charts, Alcor used to serve as an eye test. The Persian Al Kazwini stated during the 13th Century that "people tested their eyesight by this star." Mizar and Alcor were known as the "Horse and Rider" to the ancient Arabs.

The Arabian writer Al Firuzabadi, in the 14th Century referred to Alcor as Al Sadak, "The Test" or "The Riddle."

Why not test your own eyesight by looking for Alcor tonight?

Even those who live well south of the equator can see the Big Dipper now. Right after sunset, it appears to hover upside-down above the northern horizon for those down to about latitude 30 south. That includes the northern two-thirds of South America, virtually all of Africa, as well as the northern two-thirds of Australia.

Unfortunately, the familiar Dipper will not last forever.

Of the seven stars that make up this pattern, five apparently belong to a loosely joined swarm of stars, all hurtling through space at roughly the same speed and the same direction. These five stars range in distances from 78 to 84 light years from the Earth.

Two of the stars, however - Dubhe (the northern Pointer) and Alkaid (the star at the end of the handle) - are not part of the swarm and appear to be rushing at even greater speeds in the opposite direction. Alkaid is 101 light years away, while Dubhe is 124 light years distant.

These opposing motions will slowly alter the form of the Big Dipper. In short, the Dipper is slowly going to pieces.

The bent handle will bend still more as time wears on, while the bowl will spread. Granted, it will still remain a fairly convincing dipper for about the next 25,000 years, but 50,000 years from now it will be hopelessly out of shape.

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