Sasselov and Seager huddled, and together they made a fateful decision. “That was when I figured out she was a special student,” says Sasselov, “very bold.” They plunged into the infant, unproven field of exoplanets.
I imagine that must have been a pivotal moment for a young grad student. Seager swats away the idea: “You have to remember, at the time I wasn’t even sure I wanted to be a scientist.” It’s one of the many contradictions that come up in my conversations with her. She has a laserlike focus on the search for another Earth, yet shrugs off the career-defining moment that aimed her at that target. She exudes confidence but is reflexively self-questioning, frequently terminating statements with a “right?” She worries that she intimidates her students, but they speak fondly of her hard questions.
“You take a little pain in being self-critical and critical of colleagues, but the value in the long term is tremendous, and Sara gets that,” says Marcy, a close friend. “It’s a bit of a psychological quirk, to be so transparent. Sara is like the umpire of the universe. Some are balls and some are strikes, and they aren’t anything until she calls them. There is nobody else like her.”
Seager is also an adventurer by nature, something you would not necessarily guess from her controlled demeanor in an auditorium. “When I was younger I did stuff I never should have done, major white-water trips, solo trips, right at the edge of my skill,” she confesses. She met the man she would marry, Michael Wevrick, at a skiing event organized by the Wilderness Canoe Association in 1994. He was 30, she was 22. She had known him less than half a year when they set off alone for a two-month canoe trip in the Northwest Territories. “Most of the grad students were hanging out with each other, but I was just with him,” she says. Early in life, Seager seemed more intent in seeking out intense challenges than in plotting a precise destination, even when she was doing some of her most remarkable work.
In 1997, she modeled the appearance of starlight reflecting off the atmosphere of an exoplanet, showing other astronomers what to look for. In 1999, she predicted that the element sodium should leave a prominent fingerprint in light shining through the atmosphere as a planet transits in front of its star, a finding soon confirmed when a colleague at the Center for Astrophysics (and a fellow University of Toronto alum), David Charbonneau, observed just such a transiting planet. “People were really impressed, to make a prediction at that level that led to an observation,” Seager says.
With that triumph, she snagged a postdoctoral appointment at the Institute for Advanced Study in Princeton, where she once again paddled into the unknown. “I showed up and got to be the resident expert on exoplanets. I was the only one. There were no barriers,” she says. “That’s how I got into the Earth stuff.”
Small, Earth-like planets are even more challenging to observe directly than are giant gas balls like 51 Pegasi b. Nobody had cracked the problem then, and still nobody has cracked it now. But the scientific stakes could hardly be higher. Finding water vapor in the atmosphere of an Earth twin could indicate that a planet has the potential for life. Detecting molecules like oxygen and methane, which are associated with known biological processes, would be even more stunning. It would show that life really is out there, on another world, some tens of trillions of miles away. It would be, not to mince words, among the greatest discoveries ever.
“I got the job at MIT in 2007, right before my dad died,” Seager tells me. “I said, ‘Dad, this is the best I can do. I’m 35, and I’ve got tenure at MIT.’” We’ve met up at her MIT office, on the 17th floor of the Green Building, where the windows look out over the Cambridge rooftops and across the Charles River. She has positioned the chairs so we face each other easily, but we both have a view in case we need a moment to look off and think.
“He gave me his last lecture. ‘Sara, I never want to hear you say it’s the best you can do. I know there’s a better job and I know you’ll get it.’ He’d say, ‘I don’t want you to ever be limited by your own internal thinking.’ You have to understand that to understand why I’m so successful.” By this point, Seager was barely speaking with her mother or her siblings. Today she refers to herself as an orphan. “And you know about my husband, right?”
My stomach knots up at the word. “I can talk about it without crying now, so don’t worry,” she reassures me. In 2010, Wevrick started experiencing intense stomach pains. Seager’s father had described similar symptoms before dying of pancreatic cancer, so she nervously coaxed Wevrick to the doctor. After an agonizing series of medical visits, he was diagnosed with Stage 3 cancer of the small intestine. He died in July 2011, two months after her “Next 40 Years” meeting and two days after her actual 40th birthday.
The death left Seager profoundly alone. “When I was married I only had my husband, who was my best friend,” she says. “I’m not your average person, and it’s really hard for me to integrate with the real world.” Now the challenge was far greater, as the world seemed to be receding from her at the speed of light. “The most important thing that ever happened to me was my husband dying. Everything else was meaningless.”
Through the slog of depression and unexpected jolts of rage, Seager rebuilt her life. She helped her two sons through their own emotional journeys. In her hometown of Concord, Massachusetts, she connected with an informal support group of widows and made a new best friend, Melissa. She acquired a group of male buddies she calls the Council of Dads, after the book by Bruce Feiler. “Grief is not like a black hole anymore,” Seager says. “It’s sort of, let’s just say brown dwarf. It doesn’t suck you in and make you so depressed.”
Today, Seager talks about Wevrick’s death as a tragedy but also a salvation. “Before he died, I told him, ‘Your death has meaning. I’m going to go on, and I’m going to do great things.’ All he said was, ‘You would have done it anyway.’” Seager recounted the same moment for reporter Lee Billings’ book Five Billion Years of Solitude. Then she surprises me with a wistful reply to her husband’s words: “But it’s not true.”