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FEATURE


SIGNS OF LIFE IN THE COSMOS? ASTRONOMER GEORGE GATEWOOD
DISCOVERS TWO PLANETS OUTSIDE OUR SOLAR SYSTEM.

Photographs by Mark Bolster and Cornelia Karaffa, who hold copyright. Not for use without permission.




INVISIBLE DANCER
WRITTEN BY TOMMY EHRBAR


The University of Pittsburgh is becoming known as a place of contact between earth and the extraterrestrial. What in heaven's name is going on?

The world-famous Mars meteor, which caused such a sensation last summer for possibly containing fossils of tiny Martian life, was unearthed by a Pitt geological team working in Antarctica. At nearly the same time, astronomer George Gatewood, director of Pitt's Allegheny Observatory, announced the discovery of what he believes to be a solar system! He concluded that two Jupiter-sized planets are orbiting a star known as Lalande 21185, a mere galactic stone's throw of 8.1 light-years away. Coverage of the discovery ran atop page 1 of The New York Times. This story is about George Gatewood, the planetary detective.

His extraordinary findings, the latest in a fecund season of astronomical

THE REDOUBTABLE THAW REACTOR, ARMED WITH THE MULTICHANNEL ASTROMETRIC PHOTOMETER (MAP).

Photographs by Mark Bolster and Cornelia Karaffa, who hold copyright. Not for use without permission.

breakthroughs, suggests that planets (and possibly planetary life) may be common throughout the universe.

Gatewood is characteristically reserved about his claim. Still he's convinced he's found something: "I know there's something orbiting this star. I know it with a great deal of certainty. The details I don't know as well. Two planets are possible answers."

His fellow scientists are appropriately cautious. "It's not very definitive," says Anita Cochran of the University of Texas at Austin. "But Gatewood's as good as anybody in the field. I would just like to see more data."

David Black, director of the Lunar and Planetary Institute in Houston, compares Gatewood's research with reported discoveries of other planetary systems: "On the face of it, this looks more like what a planetary system should be, if that's what it is."

This discovery, which promises to shake up contemporary science, also raises anew the possibilities of intelligent life beyond Earth. It is hard to imagine life forms on stars or in the vacuum of empty space. Planets--especially warm and wet ones--are the most likely home of any little green men or women.

But whatever is up there, a wonderful story of exploration continues to unfold here on our planet at Pitt's Allegheny Observatory.

"We have loved the stars too fondly to be fearful of the night." These are the words of John Brashear, a legendary Pitt astronomer and visionary, inscribed on a plaque on his tomb in the crypt area of the observatory. Brashear saw the future for the observatory linked to the field of astrometry, the branch of astronomy that measures the motion and positions of stars. Brashear raised the funds to build the present observatory and his company built the 45-foot-long, 30-inch aperture Thaw refracting telescope still in use today. He is but one of a succession of Pitt scientists who have loved the fiery stars of the universe and the darker globes that revolve around them.

Samuel Pierpont Langley, the original director of the observatory, pioneered powered flight prior to the Wright Brothers and elevated Pitt's work in astronomy to national status.

Also in the nineteenth century, Pitt astronomer James Keeler discovered that Saturn's rings are not solid, but composed of dust and ice particles.

In recent decades, Pitt physicist Ezra Newman, along with New Zealand's Ray Kerr, discovered the first rotating black holes. And Pitt scientists David Turnshek and Cyril Hazard have made profound discoveries in extragalactic astronomy, reaching far back in time to observe the most distant galaxies, asking the Big Question: When did the universe begin?

And now the revelation of Gatewood's planets touches on the fundamental human need to know who we are, why we are here, what is our destiny. The evidence of new worlds beyond our solar system suggests another Big Question: Are we alone?

Here on Earth, home to six billion chattering, jostling, bickering souls, loneliness seems the least of humanity's problems. But consider a few facts: The universe contains trillions of stars. Up until last year, our sun was the only star we knew of with orbiting planets possibly capable of supporting any life at all, let alone intelligent life. In the grand scheme of things it seemed we were very lonely indeed.

Then came the monumental year in the history of astronomy. "We live in a time when planets are falling out of the sky," says Gatewood, his words a stunning metaphor. Within the past several months, astronomers have advanced from not knowing of any planets outside our solar system to discovering evidence of perhaps eight, Gatewood's being the closest.

In the autumn of 1995, astronomers at the Geneva Observatory in Switzerland located a planet circling the star 51 Pegasi, about 40 light-years away. The planet is about half the mass of Jupiter but has a torrid climate that would not support life. In January of 1996, researchers at San Francisco State University and the University of California at Berkeley detected at least one planet around each of two more stars: 47 Ursae Majoris in the Big Dipper, and 70 Virginis, which are both about 35 light-years away. The Virginis planet is nine times as massive as Jupiter. Water may exist on the other, which is three times Jupiter's mass.

In April of 1996, the same West Coast explorers chimed in with the discovery of what may be a planet around the star HR3522, 50 light-years away. And even earlier, radio astronomers discerned two objects orbiting a pulsar, the nearly dead cinder of a star that has exploded, collapsed, and now wanders through the cosmos.

Wanderers. This is the name ancient Greeks gave to the planets. But other civilizations were acquainted with some of the planets, even before the Greeks.

GEORGE GATEWOOD, THE PLANETARY DETECTIVE. HIS HEAVENLY INVESTIGATIONS BEGAN WHEN HE WAS A LITTLE BOY GAZING UPWARD AT LIGHTS IN THE SKY.

Photographs by Mark Bolster and Cornelia Karaffa, who hold copyright. Not for use without permission.

Five planets were known by the Babylonians as far back as 5,000 years ago: Mercury, Venus, Mars, Saturn, Jupiter. People then talked to the stars, listened to the planets, made incantations, pressed their ears to heavenly oracles. And sometimes people were awed by these creatures in the heavens, were fearful of the night.

That Earth was itself a planet was not deduced until the universe was turned upside down by Copernicus, proving that the sun, not the Earth, was the center of the solar system. Further discoveries required more powerful telescopes. First came Uranus (1781). Then Neptune (1846).Then Pluto (1930). For years, astronomers were tantalized by a putative Planet X, a 10th planet in our solar system.

The human quest to identify planets has marked centuries of frustration, false leads, and dashed hopes. In 1801, astronomer Giuseppe Piazzi discovered a muted world orbiting the sun between the planets of Mars and Jupiter. He named the new planet Ceres, leading to an international sensation. A year later, another planet was found in the same neighborhood. By 1900, astronomers had found 464 of these bodies--now known as asteroids.

Discovery of a new planet revolving around another star has been one of the holy grails of twentieth-century astronomy, spurring untold numbers of scientists to peer through their telescopes in search of brave new worlds.

It was during World War II that an astronomer by the name of Peter van de Kamp at Sproul Observatory in Pennsylvania theorized that planets could be detected by applying astrometry--the same specialty pioneered at Pitt.

New planets are extraordinarily troublesome to find. "Like discovering Klingons," Gatewood laughs, alluding to the troublesome adversaries of Star Trek fame. Planets are relatively tiny in the immensity of space, and usually get lost in the glare of the stars they orbit. So in trying to tease new planets out of hiding, scientists often resort to an indirect method. They look at stars over a long time span to see if there is a wobble in their light that could be caused by the pull of another heavenly body. In the end, finding a planet requires very sophisticated guesswork.

Gatewood likes to compare hunting for distant planets to watching a polka where one dancer is invisible: "We can see the star but not the theoretical planet dancing around it." Nevertheless, a planet would affect its partner's progress across the sky. The star would wobble, ever so slightly.

In 1943 Peter van de Kamp published some of the earliest evidence of a planet outside our solar system orbiting stars. Beginning with Barnard's Star, he compiled a list of stars surrounded by planets.

Meanwhile, at the same time, also observing the heavens, was a little boy in Florida who would later cross paths with van de Kamp.

George Gatewood, that boy, remembers one evening in particular, alive with starlight. He had followed his mother outside their house and settled into a soft spot in the grass. There he gazed upwards as his mother told him the story of the lights in the sky. She pointed out Sirius, the Dog Star! And the belt and sword of Orion! He continued to stare at the stars with imagination and ardent curiosity. George Gatewood's search for new worlds began that night.

As a young man, Gatewood proved somewhat of a wanderer himself: high school dropout, carpenter, computer troubleshooter. He recalls the night he settled on astronomy as his life's intellectual voyage: "I remember I was frustrated with the people I worked with. I looked up at the sky, at the stars, and I thought, I'll study them. They're easier."

Gatewood attended the University of South Florida, combining his fascination with statistics and the field of astrometry. Astrometry, Gatewood admits, is something that before computers, was extraordinarily tedious. "But it's a fundamental way for understanding the universe," he says. "The brightness of a star tells you nothing. Distance tells you everything--the age and architecture of the universe."

For graduate work, the young astrometrist, unsurprisingly, chose the University of Pittsburgh, with the finest astrometric observatory in the world. One hallmark of the Allegheny Observatory is a collection of glass photographic plates surveying the heavens, taken by the 30-inch Thaw refracting telescope--in all a half-million exposures arranged chronologically from 1914 to the present.

Gatewood earned his doctorate in 1972 and stayed on at Pitt as a research instructor. (In 1977, he was named director of the observatory.) In 1973, he received a phone call that would change his life. John Billingham, a California biologist, invited Gatewood to a conference on exobiology--extraterrestrial life. Gatewood was strictly a "planetary real estate man," keen on studying extraterrestrial geology, skeptical about finding company in the cosmos.

"Well, I really can't afford the trip," said Gatewood.

"We'll pay for everything," Billingham replied.

"Okay, I'm coming."

In California, Gatewood made contact of the personal kind with the forerunners of the Search for Extraterrestrial Intelligence, or SETI. This institute, whose stature was bolstered by the presence of Nobel laureates, is today privately funded, still chugging on, monitoring the sky for radio waves from another culture.

But the preferred way to track down new forms of intelligent life, the exobiologists told Gatewood, was to find new planets hospitable to life. Gatewood wrote a paper on how it could be done. "A young man paid me $100 to publish it in the journal Icarus," he recalls. "His name was Carl Sagan." Sagan and Gatewood have remained friends.

What transpired out West in the early 1970s was essentially this: Private US citizens (granted, they were rather brilliant citizens) devised strategies to discover planets and possibly intelligent life. It was this mustering of intellect and imagination, more so than the technological advancement of telescopes, that led in due time--after analyzing data bases, checking for alternative explanations--to the astronomically unprecedented year of 1995-96.

What transpired out West would produce centers for SETI's planetary probing in San Francisco and Ithaca, New York. But first, back in Pittsburgh, Gatewood opted instead to refute claims of new planets.

Particularly questionable was the list of new worlds compiled by Peter van de Kamp. At Allegheny Observatory, Gatewood reexamined van de Kamp's five best cases for planetary systems, eventually putting the question to rest: According to evidence, our solar system stood alone. A flaw in van de Kamp's telescope was later found that had distorted the star-wobble measurements.

In 1977, Gatewood received another auspicious phone call: "David Black, then an administrator at the National Aeronautics and Space Administration [NASA] called me up. He said I had a reputation for wiping out solar systems. He wondered if I could start finding planets instead of wiping them out."

His search was aided immensely by his invention of the multichannel astrometric photometer (MAP).

Previously, Gatewood relied on photographic plates as he measured star images. Now he can scrutinize sine waves, the electronic entrails of starlight recorded via the MAP system, which is mated to the bottom of the Thaw Telescope.

"This system is the result of a dream I had," says Gatewood. "I heard a talk in 1976 about why photographic astronomy is so inaccurate. Two or three mornings later, I woke up with the idea of how to do it better. I sat from morning to afternoon in my pajamas at my desk writing it down before I forgot it."

To describe the MAP's precision, Gatewood chooses a metaphor: "Imagine a faraway archer in California. As the archer fires, the telescope follows the flight of the arrow, detecting any deviation in the arrow flight the width of a dime." Gatewood patented the MAP in

ALLEGHENY OBSERVATORY, COMPLETED IN 1912, SEEMS TO FLOAT ABOVE THE TREE TOPS OF RIVERVIEW PARK LIKE A TRIPLE-PUFFED CLOUD. IT IS THE LARGEST SCIENTIFIC OBSERVATORY WITHIN A MAJOR CITY.

Photographs by Mark Bolster and Cornelia Karaffa, who hold copyright. Not for use without permission.

1983. It would prove vital to his discovery of the planets surrounding Lalande 21185.

His research on that star combines the examination of more than 60 years of photographic plates and eight years with the MAP detector. In the case of Lalande 21185, however, it was not so much the sign of a wobble but a baffling irregularity in the star's acceleration that proved the clue that broke the case. Analyzing data, Gatewood saw that the star's velocity has speeded up and slowed down as if the gravitational pull of a low-mass, orbiting companion was affecting its speed. Says Gatewood, "If these are not planets, what can be causing the acceleration? I can't think of any other explanation."

Meanwhile, Gatewood has built a new kind of MAP system, financed by NASA, and now in place on Hawaii's Keck Telescope, the world's largest optical telescope. There his star measurements will be 10 to 15 times more precise than possible at Allegheny Observatory. He is looking for planets Jupiter-sized and on down.

In his observatory office, Gatewood reflects back on his life as an astronomer, all the way back to that glistening night when his mother introduced him to the images in the sky. "I'm a frustrated spaceman. I can't go up there physically. But through my work, I can go up there."

And because of George Gatewood and the explorers like him who have produced the mid-1990s planetary bonanza, children today can gaze upon the heavens knowing there are solar systems out there beyond our own, places of strange wonder, places perhaps of new life. They can learn to love the stars (and the worlds orbiting around them) "too fondly to be fearful of the night."


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