Did you realize that if there are beings in distant space listening for signs of life on Earth, one of the first things they would hear would be "The Milton Berle Show" of 1948?

The wave front from early broadcasts of that TV series is about 175 trillion miles or 37 light-years out, a fairly feeble ripple by now, and whether any humanly conceivable device could pick it out of the ethereal jumble is another question. But it is the sort of idea that intrigues Gail Cleere at the U.S. Naval Observatory, and she mentioned it in the monthly one-page newsletter she edits there.

"I got myself in hot water over that one," she says. "I have an editorial board who check out what I write, and it made them a little nervous because it's kind of speculative. Unfortunately the sheet was already mailed."

Cleere has been writing the newsletter for four years and it is a delight. In these days of Halley's comet, it is drawing more attention than usual. Somewhat irritatingly subtitled "a popular level newsletter," it retails the month's events in the skies above Washington for a lay audience consisting of some 600 organizations, ranging from universities and libraries to news agencies and the Department of Defense.

"Venus starts out in the constellation Leo," Cleere wrote last October, "and moves into Virgo by midmonth. She certainly gets around. She flirts with Mars on the fourth, but throws him over for a handsome crescent Moon on the 12th. Look for the three of them early on the morning of the 12th."

All the planets become characters in this breezy letter. Mars "suits up for battle with his rival, the red star Antares." Mercury, "with its usual disregard for planet-watchers," slinks along just above the horizon in August. Jupiter "tunnels his way into the southeastern sky, after his January hiatus on the other side of the sun," and so on.

Moon phases and other significant dates are listed, and a rudimentary map of the horizon, looking south from Vice President Bush's porch, shows where the planets can be found during the month. (When the observatory site was still Cornelius Barber's plantation more than a century ago, slave quarters occupied the spot where the vice president's mansion was later built, it is said.)

Recently, of course, the newsletter has been preoccupied with Halley's comet, including locator maps and the Halley hotline number just installed by the observatory.

"We had a local information number last September," Cleere says, "and we thought maybe we'd get 50 calls a day. But right away we were logging 250 to 350 calls every day and overloading the system. People were so frustrated they were practically roughing up the guards at the gate. One woman told me she set her alarm for 4 a.m., but even when she called at 4 a.m. the line was busy."

Callers learn where to look for the comet on a given night. Recently a 900 number was installed: 900-410-USNO (or 8766). It can handle 14,000 calls at once, each caller being charged 50 cents.

"If there are fewer than 2,000 caller-minutes per day, the phone company charges us for them. If that happens, we'll drop the service rather than have the taxpayer stuck with the bill."

Not to worry. The first day, they had 38,000 caller-minutes; the second day, a mere 21,000.

Cleere, an art history graduate from the University of Hartford in West Hartford, Conn., had been working in museums there when she restlessly decided to try a bigger city. She was 31.

"I came to Washington in 1981 and started pounding the pavement," she says. "Reagan had just frozen government hiring -- except for Defense. So I got a list of Defense agencies, and the Naval Observatory looked like the most interesting. At the time, I didn't even know the phases of the moon."

At first it was all a bit overwhelming. Hoping to bone up on her subject in the observatory's 75,000-volume library, she found the books there incomprehensible, awash in mathematical formulas and trigonometry.

"So I went to the local library and checked out some beginners' books and "The Stars" by H.A. Ray, which has great graphics, and then Carl Sagan's books. He helped develop my love for astronomy. Helped me to understand things like the meaning of the Age of Aquarius and a lot of words I'd never heard before. 'Precession.' 'Cross-quarter days.' Things like that."

She also took a course in the cosmos at the University of Maryland. It has given her access to the math-laden language of astronomers, but she still thinks in terms of what the lay reader knows about the skies. She writes that way, too.

"Many astronomy magazines are just too complicated, I think, for someone who's not deeply involved in the subject already. I recommend the McDonald Observatory magazine at the University of Texas at Austin, for $6 a year. It has eight pages, usually."

In eight pages, it will be doing well if it makes the skies as appealing as Cleere does in one. Any month, a reader is apt to come upon a passage from Shakespeare, or an account of how Asaph Hall discovered the moons of Mars using the observatory's 26-inch telescope in 1877, or a discourse on Groundhog Day, one of the cross-quarter days midway between solstice and equinox.

When a leap-second was added to the Master Clock at the end of June 1983, the newsletter gave due warning, explaining that while the atomic clock is accurate to within one-billionth of a second a day, "the Earth's rotation is only uniform to within one-thousandth of a second per day" and tends to fall behind. When meteor showers are coming up, the newsletter reporter is on the spot with the story.

And when Dick Walker, an astronomer at the observatory's Flagstaff, Ariz., station, challenged the venerable theory that the pyramid of Cheops has an astronomically significant orientation, Cleere's communication told the how and why.

One of these days, she says, she wants to write about the accumulating technical garbage in space. It is an issue that concerns her, slightly to her own amazement.

"If anyone had told me four years ago I'd be into astronomy, I'd have said they were crazy. As it is, I have a long way to go. The other night my husband took me to Marshall, out in Virginia, to get pictures of the comet" -- her husband being astronomer Richard Schmidt of the observatory staff -- "and I hardly recognized the sky. The only sky I know is Washington's, and when I get down to second-magnitude stars I'm lost. All those stars!"