Guide to Halley's comet
For people in the northern temperate zone, now is the best time to see Halley's comet. It will be relatively bright and high enough above the west-southwest horizon for people to pick it out with binoculars, and even with the naked eye in locations well away from interfering lights. The main question, of course, is where to look. By a happy cosmic arrangement, the comet is fairly close to the bright planet Jupiter throughout the prime-time viewing period of Jan. 1-21.
Jupiter is the bright object you see low in the southwest just after dark. You really can't miss it. And once you have found it, you can locate the comet by following the accompanying charts, which have been supplied by Sky & Telescope, a leading astronomy magazine.
Alan MacRobert, the magazine's comet expert, suggests using your fist as a guide. Extend your fist at arm's length. This week, the comet will be about two fist widths above and slightly to the right of Jupiter. The charts have a fist's-width scale, like the mile scale on a road map, which you can use to help guide your search.
After about Jan. 21, the light of the waxing moon will make comet-watching difficult. Also, Comet Halley soon will swing behind the sun, making its closest approach -- which astronomers call perihelion -- on Feb. 9. It will pass our star at a distance of 54.8 million miles, speeding by at 122,000 miles an hour.
When the comet reemerges, it will be on its outward journey away from the sun and will be at its brightest as seen from Earth.
For northern observers, however, it will also be very low in the sky, if not completely out of sight. So, for the Northern Hemisphere, the best time to look for the comet is now. It won't be back again for three quarters of a century.