SCIENCE

Finder of New Worlds

MAY 12, 2014

BERKELEY, CALIF. — Last summer a homely room in the basement of a math building on the University of California campus here was ground zero in the epic quest to end cosmic loneliness.

An area rug with geometric shapes and yellow rings suggestive of planetary orbits covered the floor. A photograph of the Milky Way rising over the Hawaiian volcano Mauna Kea hung on one wall. A Naugahyde couch ran along one side of the room. Opposite it was a small refrigerator with a stash of Grape-Nuts and soy milk.

The nearest bathroom was two sets of password-protected security doors away.

This is the lair of Geoffrey W. Marcy, holder of the Watson and Marilyn Alberts Chair in the Search for Extraterrestrial Intelligence and, outside a certain robot spacecraft named Kepler, the most prolific American discoverer of alien worlds, so-called exoplanets circling stars beyond the sun.

An August evening found Dr. Marcy, a gray-goateed, twinkly-eyed presence with an aggressively empathetic air, crouched as usual in a corner in an old wooden desk chair. In front of him were computer screens and a video display connecting him to Mauna Kea, home of the twin Keck telescopes, at 40 feet in diameter the two largest in the world.

Photo

CreditIllustration by Sean McCabe; Photograph by Brian L. Frank for The New York Times

He clicked an icon on one of his screens. Three thousand miles west and 14,000 feet up, a glass container about the shape and size of a tuna can slid into place in the beam of the Keck I telescope, interposing a calibrating layer of iodine gas between it and the stars.

That was farther away, he noted, than the Hubble Space Telescope.

Queued up for observation from Mauna Kea that night were a few dozen of the most promising objects yet found by NASA’s vaunted planet-huntingKepler spacecraft.

“These are earths,” Dr. Marcy said, gesturing to the screens. “All my life I’ve pointed telescopes at stars not knowing if planets were there or not. Now we know.”

He paused.

Humanity, he said, had arrived at a special but bittersweet moment.

For thousands of years, people had looked up at the night sky wondering whether they were alone in these starry depths, whether there was any place like Earth out there, and how they would ever know. Only 20 years ago, the notion of other worlds and other life was dismissed as science fiction in respectable academic circles. Now astronomers have evidence that there are more planets than stars out there, a billion chances for Darwin, a billion potential real estate deals, a billion sci-fi dreams come true — a signature shift in cosmic perspective, in which Dr. Marcy played a leading role.

He and his colleagues were on the verge of being able to say how common Earthlike worlds were in the galaxy.

Dr. Marcy was being mentioned as a contender for the Nobel Prize.

But Kepler had broken down after four years of planet-hunting glory, and plans had collapsed for a grand, much-promoted space mission known as theTerrestrial Planet Finder, which could produce images of distant planets, sniff their atmospheres and perhaps map their geography to determine whether they were habitable or inhabited.

The field, he feared, was approaching a lull.

“What are we going to do when we’ve squeezed the last drop from Kepler?” Dr. Marcy asked. “A side of me is already grieving.”

Cosmic Dreams

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Dr. Marcy, wearing his heart on his car bumper. The astronomer has not shied away from earthbound causes, either.CreditRamin Rahimian for The New York Times

The road to the math building basement had been bumpy and long, and Dr. Marcy had the emotional bruises to show for it. He was born 59 years ago in St. Clair Shores, Mich., and had what he called a “plain vanilla” upbringing in the San Fernando Valley, imbued with a love of sports and space. Carl Sagan, the Cornell astronomer, best-selling author and host of the PBS series “Cosmos,” was his hero.

He attended U.C.L.A. and then the University of California, Santa Cruz, where he earned a Ph.D. using spectroscopic measurements to study magnetic fields in stars.

But the starry road almost ended shortly after that. Dr. Marcy won a prestigious postdoctoral fellowship to continue his magnetic research at the Mount Wilson Observatory in Pasadena, Calif., where he would be using the same telescope with which Edwin Hubble had discovered the expansion of the universe in 1929.

But Dr. Marcy’s measurements didn’t work and his previous results came under fire from other astronomers. “I got really hammered in Pasadena,” he recalled.

He was devastated. He felt stupid and ill judged. “I was so obviously a fraud,” he recalled thinking. He consulted a psychiatrist.

He wondered if he was suicidal. Then he wondered how he would know.

A turning point, he said, came while he was in the shower one morning in 1983, contemplating the end of his astronomy career. He decided that if he was going down in flames, he would go down doing something he believed in. He vowed to spend the rest of his career hunting for life in the universe. That meant searching for planets around other stars.

“You need planets,” he said. “That stands at the nexus. The logical platform for life is a planet.”

By the time he got out of the shower, his fingers were all wrinkled.

“I’ve never forgotten how miserable I was in that shower,” Dr. Marcy said.

A Fire in the Belly

When his fellowship was up in 1983, Dr. Marcy took a job teaching at San Francisco State University, far from the research limelight — it had no Ph.D. program. In his spare time, between teaching and fixing the telescope on the roof of the science building, he assembled a team of students to work on how to find planets around other stars — if they were out there.

One of his students was Mario Savio, formerly the firebrand leader of the Free Speech Movement in Berkeley in the ’60s. In his office, Dr. Marcy keeps a picture of Mr. Savio, who went on to teach physics at Sonoma State and died in 1996, at 53. He was brilliant, Dr. Marcy recalled, but “he hated writing computer code.”

A big break came when a graduate student, R. Paul Butler, who had just received an undergraduate chemistry degree, showed up in his office in the fall of 1986.

A recipe for finding planets had been laid out by the eminent astronomer Otto Struve in 1952. He pointed out that a planet would give its home star a small gravitational kick, inducing a wobble into the star’s motion as seen from Earth. In principle this could be detected by slight shifts in the wavelengths of light from the star, like theDoppler shift that causes the pitch of an ambulance siren to change as it goes past. But it required a spectrograph that could detect the shifts of one part in 10 million to see something like Jupiter.

Dr. Marcy’s new graduate student had “fire in his belly,” he recalled, and he put him to work finding a way to make a spectrograph sensitive enough to do the job. At Mount Wilson, Dr. Marcy already knew, solar astronomers calibrated their spectrographs by passing sunlight through iodine, which absorbs light at particular wavelengths, producing dark lines like the gaps in a picket fence that can serve as reference points.

After considering other ideas, he and Mr. Butler settled on iodine to calibrate their own machine. Mr. Butler built a cell to hold iodine, and in 1987 they installed it on the Shane three-meter telescope at the university’s Lick Observatory, outside San Jose, and began looking at stars.

It took them eight years to refine their techniques to find a planet. Wavelength shifts could be easily blurred, for example, by changes in the atmosphere from night to night or even moment to moment. The same effects that make stars twinkle could make their planets indistinguishable.

“We were we struggling without any road map,” said Dr. Butler, who earned a Ph.D. from the University of Maryland in the process and is now at the Carnegie Institution for Science in Washington. “Nobody knew who we were. The few people who knew what we were trying to do also knew that our quest was quixotic at best, and more likely just flat out laughable.”

Natalie Batalha, then a student at Berkeley and now a leader on the Kepler project, agreed.

Dr. Marcy, she said, “was a San Francisco State professor, hanging around Berkeley working on a program nobody had confidence that it would come to anything.”

‘Like Being on Columbus’s Ship’

Just when they were getting good at searching, Dr. Marcy and Dr. Butler were scooped.

In the fall of 1995, using the same wobble technique, a team led by Michel Mayor and Didier Queloz, of the University of Geneva, found a planetroughly half the mass of Jupiter, circling the star 51 Pegasi, about 50 light-years away, in only four days — way inside of where Mercury orbits our sun. That was a major surprise. Jupiter takes 12 years to orbit the sun, and astronomers had presumed that other planetary systems would be structured like our own.

Dr. Marcy and Dr. Butler dashed up to Lick Observatory and confirmed the new planet. They came down the mountain elated.

“It felt like being on Columbus’s ship,” Dr. Marcy said.

A Milky Way section which Kepler has scanned for planets.CreditCarter Roberts

Their own time came a few weeks later.

Early on the morning of Dec. 30, Dr. Marcy and his wife, Susan Kegley, were getting the house ready for a New Year’s Eve party, when Dr. Butler called, summoning him to the office. “All he said was ‘Geoff, get over here,’ ” Dr. Marcy recalled later.

On a graph when he got there was the up-and-down velocity cycle of a giant planet orbiting the star 70 Virginis, about 60 light-years from here.

With the next two years they found 10 more planets, generating headlines but also bruising controversy, as if Dr. Marcy had never gotten out of that shower. Some prominent astronomers argued that the Marcy-Butler team was confusing starspots or double stars for planets. The systems they were discovering were too unlike our solar system to be taken seriously.

“For three or four years, nobody believed us,” Dr. Marcy said.

At one point he was invited to give a talk at a prominent meeting in Houston, home of the Lunar and Planetary Institute. But when he got there he was ushered into a small room where half a dozen scientists interrogated him.

“It sent me into a tailspin,” Dr. Marcy said. “I was back to feeling stupid.”

Finally, in November 1999, Dr. Marcy’s group and another team, led by David Charbonneau of the Harvard-Smithsonian Center for Astrophysics, more or less simultaneously detected the shadow of a planet crossing, or “transiting,” in front of a star that already had been seen to wobble. The combination of wobble and blink was impossible to explain as anything other than a planet.

Sweet vindication at last? Perhaps, but Dr. Marcy still is quick to point out that the objections to his work were never retracted.

One of the critics, David Black, an astronomer at the Lunar and Planetary Institute in Houston, says there is no apologizing in science.

“It was never personal, as he seems to think it was for some reason that I have never been able to figure out,” Dr. Black said. “I think Geoff deserves all of the credit and praise he has gotten for his work.”

Strained Relationships

By the end of the decade Dr. Marcy and Dr. Butler, joined by Dr. Marcy’s old mentor Steven Vogt of the University of California, Santa Cruz, and Debra Fischer, now at Yale, found themselves in intense competition with Dr. Mayor’s team, often referred to as “the Swiss.” The two groups leapfrogged each other, adding to the planet count.

The constellation Cygnus, which Kepler has scanned for planets.CreditPalomar Observatory, DSS; Davide De Martin, Sky Factory; Michael Benson

Dr. Marcy and Dr. Butler were awarded the first Bioastronomy Medal of Honor by the International Astronomical Union, beginning an avalanche of medals and awards. Dr. Marcy was elected to the National Academy of Sciences and was on David Letterman’s show.

“We’re getting closer to answering the golden question of whether there is life out there,” he said in 2004. “We’re trying to find our own roots, chemically and biologically, in the stars.”

By the end of 2005, he and Dr. Butler had found 107 planets. They were the Batman and Robin of astronomy. But as the partnership grew, strains developed, with Dr. Butler feeling increasingly marginalized as reporters flocked to the eloquent and emotionally available Dr. Marcy.

Dr. Butler was more brusque. When asked for a sound bite he was more likely to grumble that he was looking forward to more data. “Some people want to be an astronomer, “ he said in an interview a few years ago. “Other people just want to play one on TV.”

Matters grew tenser in 2005, when Dr. Marcy and Dr. Mayor were awardeda $1 million prize given annually by the late Hong Kong film mogul and philanthropist Run Run Shaw.

Dr. Marcy didn’t tell the rest of his team about the prize until he returned from Hong Kong.

“I was afraid it would cause the divorce it, in fact, caused,” he said later.

In 2007 Dr. Vogt resigned from the team, saying he had lost confidence in Dr. Marcy’s leadership. Dr. Butler soon followed. The real heroes in the exoplanet story, he wrote in an email, are the astronomers who build the instruments. “In both my career and Geoff Marcy’s career, the single most important person is Steve Vogt.”

Interviewed recently, a clearly uncomfortable Dr. Marcy said he had been saddened but not surprised, comparing the rift to the breakup of the Beatles. “I would never have left Paul and Steve,” he said. “They are family, period,”

He is unapologetic about his own fame. “The news media likes me,” he said and added: “I’ve been lucky. Professional astronomers know I’ve been in the basement.” Dr. Marcy gave the bulk of his award to Cal-Santa Cruz and San Francisco State.

Dr. Batalha, of the Kepler project, said the rivalries of the early days of the exoplanet hunt had taken their toll. “It was a very intense competition,” she said. “It didn’t have to be. Everybody was racing to be first.”

The divorce had major consequences for the Automated Planet Finder, a robot telescope that Dr. Vogt and Dr. Marcy had been planning to build at Lick Observatory but was delayed for years. “In divorce, the kids are the telescopes,” she said.

Dr. Marcy eventually agreed to split the time on the telescope with the team of Dr. Vogt and Dr. Butler. They drew straws to divide the 1,700 stars on their target list and 12 years of data.

Dr. Marcy, left, and a research partner, Dr. Paul Butler, at Lick Observatory in 1997. Dr. Butler eventually resigned from Dr. Marcy’s team.CreditSusan Spann

“At the end of the day you try to be honorable,” Dr. Vogt said. It began operating this year.

The Age of Kepler

Then came Kepler.

The NASA spacecraft was launched in 2009 into an Earth-trailing orbit around the sun. Its mission was to stare at one patch of stars for four years looking for the periodic dimming that might signify planets passing in front of their suns.

The grand goal was to find Earthlike planets. The fraction of stars with such planets is known as eta-Earth; it is a key factor in the so-called Drake Equation, used to calculate the number of intelligent civilizations in the galaxy.

If we ever have the ability to step out of our cosmic cocoon, the answer could help us decide whether there will be anywhere to go, and how far away the nearest habitable planet might be.

Or as William Borucki, who spent 20 years persuading NASA to take on the Kepler project, said, “We provide the data mankind needs to move out into space.”

Kepler shook the sky as if it were a tree. More than 1,000 possible planets fell out in the first year.

Dr. Marcy had been a member of Kepler’s science team from the beginning, in 2001. But it was only in 2007, he said, that he finally had time to start going to the meetings. “It changed my life by bringing Earth-size planets into view,” he said.

“Geoff is a good guy,” said Dr. Batalha, Kepler’s deputy science director. She described him as a gracious team member, generous with credit and going out of his way to make younger astronomers feel valued.

When the Kepler astronomers realized in 2012 that they would need more time than planned for their survey, Dr. Marcy put on his “lucky underwear,” as he put it, and went to NASA headquarters to argue for more time. “This is for my students,” he said at the time.

When Kepler’s pointing system failed a year later, cutting short its planet quest, Dr. Marcy was theatrically despondent. Borrowing from a W. H Auden poem, he wrote:

Stop all the clocks, cut off the Internet,

“All my life I’ve pointed telescopes at star not knowing if planets were there or not,” Dr. Geoffrey W. Marcy said. “Now we know.”CreditEuropean Southern Observatory

Prevent the dog from barking with a juicy bone,

Let jet airplanes circle at night overhead,

Skywriting over Cygnus: Kepler is dead.

‘Chicken Geoff’

Dr. Marcy lives high in the Berkeley hills with Dr. Kegley, “wife, chemist, goddess,” as he puts it on his website — an environmental chemist and chief executive of the consulting firm Pesticide Research Institute. Their backyard is home to beehives decorated with astronomical symbols, and a flock of chickens, leading the son of one of his graduate students to call him “Chicken Geoff.”

Social consciousness is part of his identity. At Santa Cruz he ran around plastering “Men Against Rape” stickers over nude pinups in the engineering and optics shops.

At Berkeley he regularly hits the tennis courts with the women’s team. “They give me lessons,” he said. Perhaps reflecting his own years of self-doubt, his website also has a section on depression and suicide awareness. “Now I know I wasn’t alone,” he said of those dark days in Pasadena. “It’s a common phenomenon.”

Once an outsider with no future, Dr. Marcy now has his pick of collaborators and students. “My undergraduates are even smarter than my graduate students,” he said recently. He has also embraced the freedom to be outspoken.

At a meeting at M.I.T. in 2011, he startled his colleagues with a bitter tirade about their collective failure to win approval for the Terrestrial Planet Finder and challenged President Obama to make a Kennedyesque declaration that we would send a probe to Alpha Centauri. That mission would revive the agency and maybe the nation, which he says has been squandering its technological leadership in the world.

“Every young person is wondering, ‘What will my generation do that my parents didn’t do?’ ” Dr. Marcy said.

His former student Andrew W. Howard, now at the University of Hawaii, said Dr. Marcy had the ability to see the big picture and what to do next.

“He tries to zero in on the right answer,” he said. “He’s not concentrated on little details.”

This tendency was in play last fall when Erik Petigura, another of Dr. Marcy’s graduate students, announced, based on his own analysis of Kepler data, that about a fifth of the 100 billion sunlike stars in the galaxy had potentially habitable Earth-size planets. In effect he had beaten the Kepler team to the first estimate of the all-important eta-Earth.

The craft’s breakdown prompted a W.H. Auden-inspired poem by Dr. Marcy.CreditRamin Rahimian for The New York Times

Under Dr. Marcy’s direction, Mr. Petigura had spent the previous two years building and testing his own version of the computer pipeline by which Kepler data was analyzed. “Learning the occurrence of Earthlike planets can be done only once,” Dr. Marcy told him. “Erik, you’re the one; you can sleep later.”

The announcement overshadowed a major exoplanet meeting at NASA’sAmes Research Center, even as astronomers agreed that it was only the first of what would be many tries at getting eta-Earth right. Mr. Petigura’s analysis was full of assumptions and extrapolations that would be tested and retested in the coming years, astronomers said.

As Dr. Batalha, among others, pointed out, “we don’t yet have any planet candidates that are exact analogues of the Earth in terms of size, orbit or star type.”

Dr. Marcy nevertheless pronounced himself “tingly,” saying it was the most important work he had been involved in. The National Academy of Sciences recently named their paper as the best on the physical sciences published last year in The Proceedings of the National Academy of Sciences, giving it the Cozzarelli Prize.

The Stars of Summer

One thing Kepler couldn’t do without outside help was to say what these putative planets were like. By recording those blinks, it could measure the sizes of planets, but not their masses and densities. Thus there was no way to know whether these worlds were bags of gas or rocks like Earth.

That was where Dr. Marcy came in, along with the Keck telescope array and its ability to measure wobbles and masses.

“We’re pouring all our effort into planets roughly the size of Earth,” Dr. Marcy said, “not just discovering but measuring the properties of Earth-size planets.

“The Greeks would have enjoyed this,” he added. “They would understand. This is not quantum field theory.”

He was particularly interested in learning at what size a planet went from being a rock with water on it, and possibly habitable like Earth, to being gas, like Neptune. The question was of more than academic interest, since most of the Kepler planets are between Earth and Neptune in size. The data seemed to suggest, he said, that the break-even point between rocky and gaseous was about one and a half times the size of Earth. Kepler has shown that there are plenty of such worlds out there.

But without the Terrestrial Planet Finder or something like it, the search for Earth 2.0 could go only so far. You could find a planet with the mass and orbit of Earth, he explained, but “how do we know it’s not an ocean world like Kevin Costner, or dry as a bone?”

Once upon a time, astronomy was a romantic and physically grueling endeavor. Astronomers kissed their spouses and children goodbye and decamped for distant mountains, where they donned electrically heated flight suits to survive a frigid, nightlong telescope vigil.

On this night Dr. Marcy set up the telescope and its spectrometer with that tuna can of iodine, then headed home for a meal of wild salmon and tomatoes and figs from his backyard. Thus fortified, he returned to watch as Keck sent data from Hawaii to Berkeley.

In his California backyard, Dr. Marcy is known by a more informal name.CreditRamin Rahimian for The New York Times

Over the next few hours, a rogue’s gallery of stars, all of them home to suspected planets, swam into view, one after another. “They are my children,” he said.

One screen showed a star’s spectrum — a picket fence of dark and light, depending on which wavelengths of light were there.

Another screen showed previous measurements of that star’s velocity cycle as determined by earlier observations. Some looked like perfect sine waves, the signature of a star being jerked rhythmically back and forth by a planet; others were noisy clumps of points in which one could imagine regularity. Dr. Marcy provided color commentary as if he were checking up on old friends.

“This is a star pulling on a star,” he said as one came up.

He pointed to a small wiggle on another curve that suggested a second planet where there was already one. “This is frankly publishable now,” he said.

Another star, an old friend known as 16 Cygni B came up with a saw-toothed pattern of motion, the signature of an egg-shaped orbit. He recalled that he and Dr. Butler had been in his office at 4 a.m. when they first saw it — the fourth or fifth planet they had discovered — “and it’s still interesting.”

“Look at this beauty,” Dr. Marcy exclaimed. “This is Isaac Newton screaming with joy from his grave.” He continued with a chuckle: “This is my life. When we saw this, we were so excited. People didn’t realize planets could be in elliptical orbits.”

The thought brought him back to the days of being criticized.

“It feels like a black and white movie to me, really a horror film,” he said. “I was really distressed with myself.

“Kepler taught us that planets are common. We didn’t know that.”

If Mr. Petigura’s analysis was right, he said, the nearest Earthlike planets could be as close as 10 or 12 light-years away, within reach of a moderate-size telescope. “If you do T.P.F., you will not come up empty.” he said, referring to a Terrestrial Planet Finder. “You’ll have a handful of them. So we have our homework.”

By then the sky was getting cloudy in Hawaii. “Bad news, but this is astronomy,” Dr. Marcy said with a sigh as he went to look for bright stars that would punch through the clouds.

“One thing about having a big telescope,” he explained: “We can collect a lot of light through clouds.”

It was midnight when he moved on to the next star, one with five planets.

“This is a great thing,” he said. “I love this.” For him the night and the universe were young.

Our Family of the Stars

Sunday, May 18, 2014