Last Chance to see Halley's Comet

For most northerners, the middle of December will probably mark the last chance they have to glimpse Halley's Comet. In late December the moon will be too bright, and by January, the comet will be lost in the sun's glare. It will pass behind the sun in February, and the best view will come when the comet is on its outbound leg and closest to the earth next April. Unfortunately, it will not be visible from the northern latitudes then.

If clear skies prevail, the few moonless nights to either side of the new moon on December 12th should allow most Alaskans with a pair of binoculars to pick out the faint smudge of the comet. Don't expect to be overwhelmed. On the other hand, bear in mind that it won't be back for another 76 years, and that if you do see it, it will be something that only a slim minority of northerners will be able to claim (even if you have to shuffle your feet and stare at the ceiling while you tell the story to your grandkids).

Now for the hard part--how to find it. The old timers' method of using "hands" and "fingers" is useful for this purpose. Most people are proportioned so that their fingers span about equal angular distances when they extend their arm, spread their fingers, and view them with one eye. We'll call the angular separation between the point of your thumb and the tip of your little finger a "hand." By this convention a "finger," of course, is the angle subtended by the width (not length) of a finger with your arm outstretched.

For a starting point, find the Pleiades. Most people recognize this small star cluster if they see it. Some people call it the "seven sisters." My Dad used to call it the "little dipper"--which it isn't--but he pointed out that the handle always points east. The Pleiades is the very small, but conspicuous, group of faint stars that you can see in the southeast evening sky about two hands above the horizon. The cluster appears to be only about the size of a dime held at arm's length (or one finger in width). Despite its small size, this celestial gem stands out because its tiny stars are embedded in a field of glowing gas which adds to the overall luminosity.

In mid-November, Halley's Comet passed just beneath the Pleiades, and it has been steadily moving to the west (or to the right, as you face the Pleiades) at the rate of about one finger a night.

During the period of new moon in mid-December, the comet will have moved about three hands to the west, or right of the Pleiades. It will be almost level with it at six or seven in the evening, and will drop lower while the star cluster rises as the night wears on.

Another checkpoint that is fairly easy to identify is the body of the heavenly winged horse, Pegasus. This is a large square of four stars spanning about a hand between diagonally opposite stars. The center of the square also lies about three hands west of the Pleiades, and it will be tilted slightly clockwise. Comet Halley will pass beneath this square at a distance of about two-thirds the length of one of its sides.

To sum up, during November-December, Halley's Comet travels slowly across the sky along a line extending from just below the Pleiades, beneath the square of Pegasus, and further west toward its rendezvous with the sun in February. During the weekend of December 14-15, you should be able to pick up the faint glow of the comet with a good pair of binoculars if you look beneath the square of Pegasus at a distance of four or five finger widths below its lower edge.

Even though it doesn't have a tail yet (that I've been able to discern), you'll know the comet if you see it. There just aren't that many fuzzy little blobs up there. Good luck.