Scientists Tune In to Catch Sounds of Life in Deep Space

There is a “window” in deep space that astronomers call the water hole, a spot where painstaking analysis has identified the presence of hydrogen and hydroxyl molecules, the elemental components of water.

As it turns out, that same window on the microwave band is relatively quiet and free of interference from interstellar noise caused by electrons spinning in magnetic fields and other natural radio emissions.

It is that vast expanse, hundreds of thousands of light years away, that scientists think is the most likely area of the universe to search for messages from distant civilizations.

‘That’s the Hope’

Other civilizations may “congregate their signals at the water hole, at least that’s the hope,” said Thomas McDonough, president of the Planetary Society, which since 1983 has been helping finance a search at Harvard University’s Oak Ridge Observatory for signals from other worlds.

“It’s something akin to the watering hole of the Old West where the settlers gathered out in the desert,” said McDonough, who also teaches at Caltech.

The National Aeronautics and Space Administration is betting on the likelihood of extraterrestrial civilizations and is mounting the largest research and development effort to date in search of distant life.

NASA scientists are seeking $75 million in the fiscal 1988 budget to finance the system over 10 years. It is expected to be 300 times more sensitive than other systems used to eavesdrop on the universe.

There has always been a serious interest in searching for extraterrestrial life, but technology now makes in-depth searches possible, according to astronomer Carl Sagan of Cornell University.

‘We Have the Technology’

“It is not that we more fervently than any other people in the history of the world want to know the answer; it’s just that we have the technology to try to find out,” he said.

Sagan said it is possible that hundreds of distant civilizations exist out there.

“The kind of evidence we’re looking for is a radio signal or beacon, perhaps, that indicates communication in our general direction,” said Michael Klein, search-for-extraterrestrial-intelligence project manager at NASA’s Jet Propulsion Laboratory in Pasadena.

Researchers at the Jet Propulsion Laboratory are collaborating with scientists at the NASA Ames Research Center in Mountain View, Calif., which already has received $8 million to develop an observing system that will be linked to NASA’s network of ground-based antennae.

The new NASA search will explore more than 1,000 sun-like stars and scan the microwave band in search of distant neighbors in the universe. Scientists expect to begin the search in 1992 and conduct the survey over a five-year period.

“With this program we eventually would be able to expand the coverage to look at 10 million frequency channels at once,” Klein said. “And that system would be able to find either a strong or weak signal.”

If NASA allocates the $75 million needed to produce the equipment and run the project, Klein said information gained through the search could add tremendously to the body of knowledge about the universe, even if a beacon is not detected.

“I view this experiment as an attempt to try to learn how abundant life might be in the universe,” Klein said. “This is just a moderate-sized program as far as NASA’s concerned, but it has the potential to do so much.”

From NASA’s Deep Space Network antennae in the California desert, Australia and Spain, incoming messages from anywhere in the universe could be detected regardless of Earth’s angle during the spin on its axis or rotation around the sun.

In addition to this network, Klein said NASA scientists also would connect computers and microwave monitors to the National Science Foundation’s massive 1,000-foot diameter radio telescope near Arecibo, Puerto Rico.

That device, among the most sensitive high-powered radio telescopes, is in a quiet mountainous area of the Caribbean island and has been used by Paul Horowitz, director of Harvard’s search-for-extraterrestrial-intelligence program, to search for distant signals in the universe.

Multichannel Analyzer

The NASA project will use a multichannel analyzer, a high-speed computerized receiver that would split a radio signal from the antennae in Spain, California and Australia into 10 million channels. A second computer would eliminate signals that may have been generated by known sources.

Klein said the search will be conducted by moving the radio telescopes across the sky at a constant rate--an “all-sky survey,” as the observation method is called.

The other part of the survey involves searching for weak radio signals originating from sun-type stars as far away as 80 light years. One light year is equivalent to 6 trillion miles.

Klein said the objective is to test the hypothesis that extraterrestrial civilizations are transmitting radio signals that Earth-based instruments are sensitive enough to detect.

“We can conclude that the probability of life being out there certainly is not zero,” Klein said. “It’s presumptuous to think that life would only occur here. I think it’s more likely that some civilizations are ahead of us and others are behind us in terms of intelligence.”

Klein, however, doubts that distant civilizations would attempt traveling to Earth because such a trip could take hundreds of light years to complete.

Instead, scientists say a radio signal traveling at the speed of light, 186,000 miles per second, is the most efficient method of communicating between stars and galaxies.

‘Fantastically Cheap’

Sagan said, “A radio signal is fantastically cheap.

“You can send the equivalent information contained in the entire Encyclopedia Britannica to the nearest star in about a week, and the cost is about the same as sending a telegram to China.”

Programs searching for extraterrestrial intelligence assume the existence of extraterrestrial civilizations that are at least as intelligent as humans and are concerned with economics and speed in relaying messages through the universe.

Depending on the location of another civilization, it could take hundreds, thousands or even millions of years for a message traveling the speed of light to be detected by Earth-based instruments.

“There’s no way we could detect guys who are stupider than us,” said McDonough of the Planetary Society. “I like to think that there is a group of interstellar hackers out there who spend their time trying to communicate with primitive civilizations like ours.”

NASA plans to try only to detect signals from distant worlds and does not plan to send any.

“We don’t have to send messages because our television programs work perfectly well as messages,” said Frank Drake, an astronomer and dean of natural sciences at UC Santa Cruz.

“There’s now a shell around the Earth about 40 light years in radius, and it’s full of old television programs,” Drake said.

Most of the earliest television programs, which were sent into space as well as to rooftop antennae, are just beginning to reach some of the more distant stars in the galaxy, possibly entertaining or puzzling a distant civilization with “I Love Lucy,” “Kukla, Fran and Ollie” and the “Ed Sullivan Show.”

“A few lucky ones have gotten Super Bowl I,” he said.

But some astronomers are not quite as optimistic about the existence of other worlds as supporters of search-for-extraterrestrial-intelligence projects.

“My own personal view is that none of them will succeed,” UCLA astronomy professor Benjamin Zuckerman said of all the search-for-extraterrestrial-intelligence projects under way throughout the country and around the world, including NASA’s ambitious proposal.

“Intelligent life is a very rare commodity,” said Zuckerman, who has conducted scientific conferences questioning the existence of extraterrestrials and co-edited the book titled, “Extraterrestrials: Where Are They?” “The question really is where are they? Or, if there are as many as they (scientists searching for extraterrestrial intelligence) say, why haven’t we seen them?

“Because these questions have not been answered is the basic reason why people like myself believe there can’t be civilizations like our own in this galaxy.”

Zuckerman said he does not “completely” rule out the possibility of “a few” distant civilizations, but he added: “Who knows what kind of sociology these civilizations would have? Who says they haven’t given up on technology and gone back to nature?”

No Beacons Detected

As far as scientists who search for extraterrestrial intelligence can determine, no beacons have been detected, although “there been some interesting signals, but when we’ve gone back to check them, they weren’t there,” Klein said.

Drake, however, said studies of organic molecules extracted from meteorites and the discovery two years ago of an apparent planet orbiting what appears to be a star like the sun are finds that are viewed as most encouraging to scientists searching for extraterrestrial intelligence.

He said the planet-like object accompanying a star known as van Biesbroeck 8 in the Milky Way suggests that other planetary systems, much like our own, may have formed elsewhere in the galaxy.

Scientists from fields as diverse as astronomy and molecular biology suggest that chemicals and events similar to those that produced life on Earth could have occurred elsewhere in the universe, possibly in the Milky Way.

Tests of chemicals in meteorites and interstellar dust clouds have revealed the presence of a wide range of organic molecules, most notably those required to construct proteins and the nucleic acids that form the genetic code for life on Earth.

Dr. Cyril Ponnamperuma, who chairs the Laboratory of Evolution at the University of Maryland, suggests that the chemical reactions that led to life on Earth could have occurred anywhere in the universe.

He cited the pioneering experiment in the 1950s by University of Chicago scientists Harold Urey and Stanley Miller. They synthesized amino acids, the building blocks of proteins, by sending electric sparks through a mixture of hydrogen, water vapor, ammonia and methane. All of those molecules have been identified in the universe by way of spectroscopic observations.

“What this means is extraterrestrial life is more likely to be chemically similar to life on this planet,” Ponnamperuma said. “Also, it simplifies the scenario required for the evolution of life from non-life on Earth.”

The chemist has also produced in the laboratory the building blocks of biological molecules and the four bases of DNA, the genetic material of life on Earth.

He suggests that the synthesis of DNA--the basic chemistry of genes--could have occurred naturally elsewhere in the universe, much in the same way DNA evolved as the genetic blueprint for all forms of life on Earth.

‘Genetic Accidents’

“We look the way we do because of a series of genetic accidents,” said Sagan, who underscored that even if the same chemicals exist throughout the universe, the genetic events that produced life on Earth would not have occurred at the same time and in the same fashion elsewhere in the cosmos.

“If history on Earth had been slightly different, people might now be lizards or we could have been octopi,” McDonough said. “Life on Earth is the product of a series of accidents throughout billions of years of evolution.”

Said Sagan: “We’re in no position to say what an extraterrestrial would look like, and that’s why it is important to go looking for them. And if you want my guess, they won’t look anything like us.

“The question of life elsewhere in the universe is extremely important to scientists and especially for biology. It speaks specifically to what we are and how common is this thing we call intelligence.

“This is the first time in our existence that we can address resources to it.”