For millions unborn or inattentive on its visit in 1910, Halley's Comet will be visible high in the southern sky on the first clear night this month -- Saturday, if the weather forecast holds up.
Binoculars are still needed to find the comet, still more than 55 million miles from Earth. And it won't look like a comet because it is too far from the sun to have grown a noticeable tail.
But start looking 60 degrees above the horizon about an hour and 45 minutes after sunset, between about 7 and 7:30 p.m., in the direction of the "great square" of Pegasus, the four stars that form a square between the constellations Andromeda and Pegasus.
The great square is about 15 degrees above the constellation Pisces. The comet will be directly south of the star in the lower left-hand corner of the square, a star called Gamma Pegasus.
"It won't be a pinpoint of light like a star," said Dr. Richard E. Schmidt of the Naval Observatory here. "It will look like thin moonlit clouds with a wispy tail to the southwest. It will be brightest in the center, as if it were a star surrounded by clouds."
The first rule of comet viewing is to get away from city lights, which wash out any hope of seeing the comet.
Leaving the city also helps to leave air pollution behind. Haze and dust are the worst offenders. Even moonlight is a pollutant, so don't expect to see the comet after the moon rises around midnight on Friday, 1:48 a.m. on Saturday or 3 a.m. on Sunday.
"There will be good viewing until Dec. 19," Schmidt said. "That's the night of the quarter moon, which puts the moon too close to the comet. The worst night this month will be Dec. 27, the night of the full moon when the moon washes everything else out of the sky."
The comet is on the verge of being visible to the naked eye, but won't really come into unaided view until later this month or even early next month.
"If you're in a dark region like the Skyline Drive and know exactly where to look, you might see it with the naked eye early this month," Schmidt said. "My advice right now is to find a friend who knows stars and have him or her be your Seeing Eye dog in this case."
By Dec. 15, the comet will be in the middle of the constellation Pisces sinking slowly toward the horizon and moving in a southwest direction. You will find it about 55 degrees above the horizon Dec. 15 just below a group of six stars known as "The Circlet" because they form what looks like a rough circle. This is the last group of stars that can be used as a guide to find the comet in Pisces.
Once the comet has passed through Pisces it moves into Aquarius, where it stays through Christmas and the first 15 days of January. It will be about 50 degrees above the horizon and beginning to sink more rapidly.
Halley's Comet stays so long in Aquarius because the constellation itself is so big and because the viewing angle from Earth makes it appear that the comet is not moving as fast.
"A good game to play is to lock onto the comet for 30 minutes after you've found it," Schmidt said. "In that time, you will sense that it has moved."
By New Year's Day, Halley will be well into Aquarius and should be visible to the naked eye. It will be getting brighter and forming a more noticeable tail, but it will also be sinking rapidly and by Jan. 18 will be lost in the glare of the sun.
"It will be lost behind the sun until the end of February," Schmidt said. "The next time to spot the comet will be Feb. 25 when it emerges from the sun's glare in the constellation Capricorn."
The best time of all to see the comet will be in March and April, when it steers clear of the sun. The head will be brightest and the tail longest, perhaps 30 million miles.
In 1981, astronomers were gloomily predicting a poor "apparition" for Halley on its outbound leg. But amateur astronomers John Bortle and Charles Morris recalculated the brightness chart and decided it would be brighter than predicted next spring.