by Lee Billings
After submitting, Anglada closely watched the incoming traffic to his personal website, reasoning that he could gauge when his proposal was examined by looking for members of the ESO review committee who would visit to examine his credentials. In mid-November, his site received a pulse of traffic associated with computers in Munich, where the ESO review committee was based, as well as from computers in Geneva, Porto, Paris, and Santiago—all cities hosting HARPS team members. Each visitor browsed for minutes, then departed and did not return. On November 21, the HARPS team uploaded a 77-page preprint to a public online repository. The preprint was a draft version of a paper submitted to a prominent peer-reviewed journal, summarizing six years of HARPS observations, from 2003 to 2009. The astronomer Xavier Bonfils, a senior HARPS team member, was the first author. In a table on page three and a paragraph on page eight, the team noted its detection of a super-Earth in a 28-day orbit around GJ 667C, and referred interested readers to a more detailed forthcoming paper that was in the midst of preparation. Later, Anglada would learn his HARPS proposal had been rejected.
Vogt was the first to see the Swiss preprint claiming discovery of GJ 667Cc. He immediately sent a terse e-mail to Anglada and Butler: “We’ve been scooped.” Anglada was crestfallen; he read the preprint, then left his Carnegie office for a long walk. That night he couldn’t sleep.
“I was very upset,” he recalled. “So I reread the preprint again and started cataloging strange things. It didn’t include any detailed analysis of the system’s dynamics, and it barely discussed the 91-day signal. It said that the evidence for GJ 667Cc would be presented in a paper that was in preparation that would be submitted in future, yet it also said this paper had already announced GJ 667Cc—it was a self-contradictory statement that didn’t seem to be a proper way to formalize the discovery.” Looking at the table listing the planet’s orbital parameters, Anglada noticed something odd. The table listed GJ 667Cc’s orbital period as 28 days, but the size of its listed orbit erroneously corresponded to that of an orbit of 91 days, as if GJ 667Cc’s entry had at one time concerned the 91-day rather than the 28-day signal.
“It could all have been coincidence,” Anglada told me. “But I couldn’t help feeling suspicious. If they had seen this signal in their data back in 2008, why did they wait three years, only to announce the planet in such a curious way the week after my HARPS proposal was reviewed? Why did the orbital size and period not match? I started to feel angry, and decided I should go on and push ahead with what I had found.” Within a week, Anglada had completed his paper and submitted it to the Astrophysical Journal Letters, which published it in February 2012—beating the HARPS team to peer-reviewed publication. UC Santa Cruz issued a press release crediting Anglada, Butler, Vogt, and their collaborators with GJ 667Cc’s discovery.
Bonfils and the rest of the HARPS team were aghast. They were the planet’s true discoverers, they argued, as established by their November preprint. The controversy remained unaddressed until June, when Anglada and Bonfils agreed to a private meeting at a coffee shop outside a conference in Barcelona. Bonfils told Anglada that the HARPS team had already known of GJ 667Cc back in 2009 when they had announced their discovery of the system’s other world in a 7-day orbit. They had submitted their 77-page survey paper for peer-reviewed publication in April of 2009, Bonfils said, but feedback from one of the reviewers had delayed the preprint’s public release until November 2011. Anglada replied that the timing of the preprint was irrelevant, because it did not contain enough detailed information to support the HARPS team’s discovery claims. Anyone could report wobbling stars, but to prove the wobbles were planets they had to show their analytical work. If published analysis was the test, Bonfils countered, then it was one Anglada’s paper had still failed, because it contained the same mistake Butler and Vogt had made with the Gliese 581 system. Pooling HARPS data with that from lesser spectrometers such as HIRES, Bonfils maintained, would degrade the RV data and only increase the likelihood of false alarms; in contrast, the HARPS team’s preprint was a valid discovery paper. By the time they finished their coffees, neither man had given any ground, and the tension between them had only grown.
I reached Bonfils by telephone a month after his meeting with Anglada. He sounded pained.
“They are trying to take credit for a discovery they did not make. It is as basic as that. It’s not by hazard that we found this planet—it was on purpose. GJ 667C is one of our survey’s most-sampled stars. That’s why [Anglada] looked at it. HARPS was built by our team, and the scientific program and observations were done by our team. Most of the data reduction was already done and provided in our public data. I think it would be a pity if the guys who made the instruments and designed and performed the program of observations did not receive credit for their work. I’m a supporter of public data, but I had long feared someone would try to publish our data before us, and it has now happened. Right now this community rests on good behavior and gentlemen’s agreements.”
Nothing, nothing at all, Bonfils insisted, had precipitated the preprint’s release in November 2011 after years of delay. It had been simple serendipity. “It was slow,” he acknowledged. “I’m not proud of how long it took.” He offered his own view of what had motivated the fight over public HARPS data. “Before, it was Marcy, Butler, Vogt, Fischer. Now they have split, the group has almost evaporated. I don’t know Vogt or Butler personally, I have met Anglada once only. But I think there is, how to say, tension? You see it in their papers, in the language and accusations. A hunger, an aggression. I think it has become more difficult for them to get the observing time they need.”
For the time being, Anglada told me, he had no plans to stop examining the public HARPS data for new discoveries. “People seem to think GJ 667Cc was a one-off thing, or that I got lucky looking where I did, but that’s not true,” he said. “This is really just the beginning of a bigger story. When you improve precision as I have, more things appear. The population of exoplanets is growing exponentially as we become sensitive to lower masses. I’ve looked at hundreds of systems now in their database. A lot of objects are showing up.”
Despite working closely with Vogt and Butler, Laughlin had managed to stay above the battle for the first potentially habitable exoplanets. He had not been directly involved with the detections, announcements, and criticisms of Gliese 581g or GJ 667Cc, and he preferred to keep it that way. He held a longer view on the controversy surrounding them. In his mind, the strife between teams and the explosive expansion of exoplanetology were just growing pains, symptoms of a field struggling with its own imminent maturity.
“Just finding any planet around another star isn’t as newsworthy or appealing as it used to be,” Laughlin told me one afternoon in Santa Cruz. “That alone won’t get you a flashy press conference and the front pages of newspapers and lurid artist’s renditions like it would have ten, twenty years ago. Ten, twenty years from now, just finding an Earth-mass planet in the habitable zone of a Sun-like star probably won’t be a big deal, either. Historians may look back and shake their heads at this period, when astronomers were regularly claiming to have found the ‘first habitable planet,’ but only in comparison to the last, previous ‘first habitable planet.’ It’s my sense they’ll remember this time as when the Heroic Age of extrasolar planet discovery came to a close.”
“The real story,” Marcy once remarked to me, “isn’t the validity or the timing of discovery of any particular Earth-size, Earth-mass planet. Simply detecting one of these things does not overturn astrophysics or planetary science. The real story here is the amazing plausibility of detecting them at all, the fact that from our perch upon this speck of dust, we have come to the point where we are on the threshold of these sorts of discoveries. It’s as surprising as an ant, living its life among other ants on an anthill, somehow calculating the size of the solar system. All we do is collect photons from the stars, and from that we can deduce the existence of planets and the scale and structure and f
uture of the whole shooting match. It’s crazy.”
When, after repeated setbacks and delays, the APF at Lick Observatory finally became fully operational in 2013, observing time was evenly divided between the Marcy and Butler-Vogt teams. The break had been complete, and seemed irreversible: Butler and Marcy had not spoken since 2007, and perhaps never would again. And yet on nights when the sky above Mount Hamilton was dark and clear, they could be found virtually side by side, as their shared robotic telescope slewed between separate, distant points, building fractured empires among the stars.
The Worth of a World
Back in 2009, less than a week after a Delta II rocket launched Kepler into planet-hunting history, Laughlin had quietly posted a strange, half-whimsical equation on his blog systemic, at oklo.org. In a series of subsequent posts, he explained how the long string of obscure variables and weighted functions could be used to crudely quantify the value of any terrestrial exoplanets that Kepler and the handful of other leading surveys might soon discover. It was, he said, an attempt to judge whether any particular “Earth-like” world was worthy of legitimate scientific excitement, independent of media hype. After plugging in a few key parameters—such as a planet’s mass, its estimated temperature, and the age and type of its star—Laughlin’s equation would generate a value, in U.S. dollars, that could be assigned to that particular world. Small, rocky worlds in clement orbits around middle-aged, middle-of-the-road stars similar to the Sun merited the highest values, as those planets presumably offered the best chance for harboring complex biospheres that could eventually be detected by future space telescopes. For a planet to be worthy of wide attention, Laughlin opined, it would need to at least break the million-dollar mark.
Laughlin drew his economic baselines from simple math, dividing Kepler’s federally funded $600 million price tag by 100, a conservative estimate of how many terrestrial planets the space telescope would discover during its lifetime. If such planets could be considered commodities, the math suggested that the 2009 market price, as determined by U.S. taxpayers, could be set at $6 million per world—a value that could drop over time if small rocky planets began to overflow astronomers’ coffers. If, however, Kepler found a terrestrial world in the middle of a Sun-like star’s habitable zone, Laughlin’s test runs suggested such a planet’s value could exceed $30 million in his equation. Zarmina’s World, if it existed, garnered a value of around $60,000. GJ 667Cc was worth even less. According to Laughlin’s calculations, Kepler’s first million-dollar candidates appeared in February 2012. Several more would follow, bearing names such as Kepler-62f and Kepler-69c, until the Kepler spacecraft suffered a crippling malfunction in May of 2013 that all but ended its primary mission.
The cleverest part of Laughlin’s valuation equation was its treatment of a planet’s home star, which allowed his numerical scrutiny to be extended to the worlds in our own solar system. Photons, not dollars, are a planet hunter’s fundamental currency, as they are what allow a planet to be not only detected but also subsequently characterized. Generally speaking, the more photons astronomers can gather from an exoplanetary system, the more they can learn about it. Stars and planets nearer to our solar system are brighter in our skies due to their close proximity, and hence more valuable, providing floods of useful photons where more distant objects would only offer trickles. This facet was why so many of Kepler’s small planets would struggle to reach a valuation of even a million dollars: the Kepler field stars were far away, and thus very dim. The brightest star visible in the solar system by many orders of magnitude is, of course, the Sun, which has the capacity to send local planetary valuations into truly astronomical territory.
Based on the early-twentieth-century notion of Venus’s clouds as reflective shielding against the potent solar flux, Laughlin’s equation pegged the planet’s value at one and a half quadrillion dollars—$1,500 trillion. Evaluating Venus based on its actual runaway-greenhouse surface temperature gave the planet a value of a trillionth of one cent. Laughlin sometimes compared such discrepancies in planets’ values to the dot-com stock bubble of the mid- to late-1990s, when companies leveraged investors’ irrational exuberance into billion-dollar valuations, only to crater when the bubble collapsed and their true, far lower values were revealed. When he ran his valuation equation for our own planet, Laughlin obtained a value of approximately five quadrillion dollars—roughly one hundred times the global gross domestic product, and, he reckoned, a handy approximation of the economic value of humanity’s accumulated technological infrastructure. Searching for other habitable worlds, it seemed, was rather like speculating in a galactic-scale stock market.
Laughlin had also run his equation on a purely hypothetical Earth-size planet in the habitable zone of one of the two Sun-like stars in the Alpha Centauri system. He obtained a value of $6.5 billion—coincidentally about the same amount of money astronomers often estimate would be needed to build a space telescope capable of seeking signs of life on such a world. If humans actually voyaged there, Laughlin once pointed out to me, the star would become ever brighter, until it was a new Sun in a new sky of a New World. “So in going there, you have this ability to intrinsically increase value. And that’s an exciting thing because it ultimately provides a profit motive for perhaps going out and making a go of it with these planets. This is saying that something that is several billion dollars on Earth could be, if you go there, a quadrillion-dollar payoff.”
Months before our encounter at Tomales Bay, I had interviewed Laughlin about his equation for an article I published on the website BoingBoing.net. The article’s contents made their way into the mainstream media, which focused far more on Laughlin’s musing valuation of our world than on the worth of exoplanets. Stories appeared bearing headlines such as “Earth is worth £3,000 trillion, according to scientist’s new planet valuing formula” (Daily Mail, February 28, 2011) and “Wanna buy the Earth? It’ll cost you $5 quadrillion” (Toronto Sun, March 1, 2011). Angry e-mails began piling up in Laughlin’s inbox, and television and radio stations called hoping to interview the mad scientist who so arrogantly placed a price on our planet. Laughlin was taken aback—he had emphasized, both in his posts and in his discussions with me, that his equation did not and could not assess the worth of, for instance, a human life or a new idea. Soon the story was churned out of view by the voracious 24/7 news cycle, but the sensational headlines left a lingering impression. Before Laughlin’s talk at the Miller Institute symposium, I overheard one member of the audience jokingly refer to him as “The Man Who Sold the World.”
The day after his presentation, I was in the front passenger seat of Laughlin’s car as he drove us back down to Santa Cruz. In the back seat sat Taylor Ricketts, a World Wildlife Fund ecologist who had given a talk about “natural capital,” the economic benefits of material goods and services provided by Earth’s biosphere. Ricketts was part of a growing interdisciplinary push to study ecology in the context of economics, a field interested in not only the monetary value of, for instance, a pristine forest, but how that value might change if the forest was converted to pasture, or a parking lot.
At the time, Ricketts was a few months away from becoming director of the University of Vermont’s Gund Institute for Ecological Economics, which he mentioned in passing not long after we crossed over the Golden Gate Bridge and began to drive on Highway 101 through downtown San Francisco. Gund’s previous director, an ecologist named Robert Costanza, had “gotten into trouble” back in 1997 for a Nature paper in which he tried to estimate the value of the planet, Ricketts said.
Laughlin’s bushy eyebrows bounced up as he looked back at Ricketts in the rearview mirror. “What was the figure Costanza came up with?”
“Thirty-three trillion dollars per year, for all the world’s ecosystems.”
“I don’t know why you’d get in trouble for that,” Laughlin sighed.
“He made several basic economic mistakes that made his final figure essentially unsupportable,” Ricketts sai
d. “But more fundamentally, his critics just said, ‘Thirty-three trillion dollars is a nice underestimate of infinity.’ The value of the planet to us is infinite, because if all the ecosystems go away, life ends. For all of us. So there’s not really a valid reason to put a number on that. Some people said he was silly for making his estimate, and others called him brave for trying. It’s hard to know how much it has affected his career, but his name is kind of shackled to that paper.”
Minutes passed. We eased into a snarl of afternoon traffic congested by a red stoplight at the crest of a long, high hill.
“So, an interesting counterargument to the ‘infinite’ value of the Earth is the fact that at some point this will all go away,” Laughlin said. His eyes darted to sweep over the pedestrians slowly scaling the steep, tree-lined sidewalk, the cars idling their engines in the street, the people wandering in and out of boxy wooden row houses and tall office buildings of glass and steel, before his gaze finally came to rest back in the rearview. “And not because of anything we’re doing, but because the Sun will evolve into a red giant and destroy the Earth. I don’t think that’s something for which we just have to sit down and acquiesce. So this becomes a question of where we are willing to begin talking about timescales on which our actions could have some conceivable utility.”
“That’s true,” Ricketts said. “But economics is about how you make decisions under scarcity, right? You can’t do everything, so how do you choose what to do and what not to do? You can’t buy everything, so how do you choose what to buy and what not to buy? The reason to put value on things is to inform a choice you might have—that’s the fundamental reason for economics to be. To place a value on the Earth . . .” He trailed off for a moment, finding his words. “I don’t understand what the option or choice is there, what we would do with that information. It’s not like we have the option of not being destroyed by the Sun, and that’s probably why economists think a planetary valuation is a bit silly.”
