ALIENS HUNT ALLURE : MASTER ESSAY

Another false alarm in the hunt for aliens. A new Chinese telescope found a 'suspicious signal' that hasn't checked out.

Fifty years ago, NASA published a fat, 253-page book titled, ''Project Cyclops.'' It summarized the results of a NASA workshop on how to detect alien civilizations. It was a project that launched a thousand interstellar dreams. 

What was needed, the assembled group of astronomers, engineers and biologists concluded, was Cyclops, a vast array of radio telescopes with as many as a thousand 100-meter diameter antennas.

At the time, the project would have cost $10 billion. It could, the astronomers said, detect alien signals from as far away as 1,000 light-years.

The report kicked off with a quotation from the astronomer Frank Drake, now an emeritus professor at the University of California, Santa Cruz :

''At this very minute, with almost absolute certainty, radio waves sent forth by other intelligent civilizations are falling on the earth. A telescope can be built that, pointed in the right place and tuned to the right frequency, could discover these waves.

Someday, from somewhere out among the stars, will come the answers to many of the oldest, most important and most exciting questions mankind has asked.''

The Cyclops report would become a bible for a generation of astronomers drawn to the dream that science could answer existential questions.

''For the every first time, we had technology where we could do an experiment instead of asking priests and philosophers,'' Jill Tarter, who read the report when she was a graduate student and who has devoted her life to the search for extraterrestrial intelligence, said in an interview a decade ago.

I was reminded of Cyclops and the work it inspired this month, when word flashed around the world that Chinese astronomers had detected a radio signal that had the characteristics of being from an  extraterrestrial civilization - namely, it had a very bandwidth at a frequency of 140,604 MHz, a precision nature doesn't usually achieve on its own.

They made the detection using a giant new telescope called the Five-hundred meter Aperture Spherical radio telescope, or FAST.

The telescope was pointed in the direction of an exoplanet named Kepler 438b, a rocky planet about 1.5 times the size of Earth that orbits in so-called habitable zone of Kepler 438, a red dwarf star hundreds of light years from here, in the constellation Lyra.

It has an estimated surface temperature of 37 degrees Fahrenheit, or almost 3 degrees Celsius, making it a candidate to harbor life.

Just as quickly, however, an article reporting the discovery in the state-run newspaper ''Science and Technology Daily'' vanished. And Chinese astronomers were pouring cold water on the result.

Zhang Tong-jie, the chief scientist of China ET Civilization Research Group, was quoted by Andrew Jones, a journalist who tracks Chinese space and astronomy developments, as saying, ''The possibility that the suspicious signal is some kind of radio interference is also very high, and it needs to be further confirmed or ruled out. This may be a long process.''

Dan Werthimer, of the University of California, Berkeley, who is among the authors of a scientific paper on the signal, was more blunt.

''These signals are from radio interference; they are due to radio pollution from earthlings, not from E.T.'' he wrote in an email.

This has become a familiar story. For half a century, SETI, or the search for extraterrestrial intelligence, has been a game of whack-a-mole, finding promising signals before tracking them down to orbiting satellites, microwave ovens and other earthly sources.

Dr. Drake himself pointed a radio telescope at a pair of stars in 1960 and soon thought he had struck gold, only to find that the signal was a stray radar.

More recently, a signal that appeared to be coming from the direction of the sun's closest stellar neighbor, Proxima Centauri, was tracked down to radio interference in Australia.

The Publishing continues. The World Students Society thanks author Dennis Overbye.