On New Year's Day, I awoke hoping that '88 would usher in the Era of Reason. Then I read Weekend in The Post.

Its cover page announces: "Modern Astrology: The '88 Forecast." And it shows a man working at a computer, with stars in the background. Inside, a three-page-long article gives astrological predictions.

"Modern astrology," like its ancient counterpart, is gibberish -- except now, with a computer, you can produce it faster and seem more authoritative. After centuries, astrologers still provide no verification for their beliefs.

Yet, here the influential Post prominently displays this archaic superstition. Presented seriously, the article has no disclaimer (WARNING: BELIEVING THIS COULD BE HAZARDOUS TO YOUR THINKING). Will The Post next highlight voodoo or palmistry? You expect such hype in grocery store tabloids. But in The Post?

Ironically, a tabloid once explained the quintessential difference between astronomy (the science) and astrology (the pseudoscience):

"Astronomy is when you look at the night sky and see nothing but stars and planets. Astrology is when you look at the night sky and see dragons and virgins and other creepy things."

Richard Berendzen

The writer is president of The American University and a professor of astronomy.

Readers of The Post are deeply indebted to Washington astrologer Warren Kinsman and The Post's own in-house astrology expert, Carl Kramer, for their analysis of the planetary positions to provide us with revelations of the year to come, which indicate that "money will be the dominating factor of the year." We nonastrology experts could never have forecast this in view of the fact that The Post's news columns have been reporting a strong U.S. trade surplus, a very favorable dollar exchange rate, a federal budget surplus and an ever-rising stock market, which has never once stumbled.

Their astrological forecast of a "rise in the incidence of AIDS" is equally unexpected and doubtless will come as a great surprise to those who have spent the last several years living in the heartlands of Tibet and Antarctica.

Philip J. Klass

On New Year's Day you ran an extensive article on astrology. I forget the author's name, but I recall that you described him as ''an amateur astrologer living in the Washington area.''

I happen to be an amateur tea-leaf reader living in the area. I'm sure you would be pleased to publish an article I could write for you on the techniques and cosmic significance of tea-leaf reading.

How much would you pay for such an article? Please answer right away. I need the money.

Charles H. Shaw

Astrology may be harmless fun for some. But in a society that seems to be sinking deeper into the muck of irrationalism and ignorance, don't you think The Post has some responsibility toward trying to reverse this trend? Even if you feel no call toward such a cause, I'd think you'd still be concerned about what lending credibility to astrology does to your credibility as journalists. Can you imagine local broadcast journalism having the same standards? ''Okay, folks, that's the news, weather and sports. And now here's Carl Kramer with your horoscope . . . ''

Gerald Bishop