Block Out the Star to See Life
Achieving totality with astrophysicists in Idaho
In Weiser, Idaho, a tribe of astrophysicists whooped and danced as the moon blocked out the sun. They were ostensibly in town for a Exoclipse, a conference at Boise State on exoplanets, but that was just an excuse to witness totality with other astrophysicists from around the globe.
I had been traveling with one of them, Daniel Angerhausen, for two weeks. Angerhausen, another astrophysicist named Gavin Coleman, and I gaped at the sky from a grassy patch next to the track of a local high school. In the distance, two spiders the size of tractor trailers trawled the yellow hills.
For 90 minutes, the sun wrestled the moon. Pinned for two full minutes, the sun flailed its coronal arms like a trapped jellyfish. It was the first time in 38 years that such a thing had been visible in the lower 48. Not since 1918 had a solar eclipse transited the United States from coast to coast.
Why Astrophysicists Care About Eclipses
Astronomers are interested in eclipses for many reasons, but most involve opportunities to view stuff that’s obscured by the brightness of the sun. The sun’s corona, for example, is much larger and hotter than the sun itself, and no one knows why. A total solar eclipse is the only time the corona can be naturally viewed on its own. The same goes for nearby planets, which are invisible during the day because the sun is too bright.
Then there are the exoplanets: celestial bodies that exist outside our solar system. We’ve speculated about them for millennia, but the first real exoplanet, 51 Pegasi b, was detected only 25 years ago. Exoplanets are so hard to detect because they are drowned out by light of their stars. One way of finding them is called transit photometry, which relies on tiny, distant eclipses. When an exoplanet passes over the light of its star, it blocks it out and becomes briefly detectable.
Angerhausen specializes in the study of exoplanets using transit photometry.
“The big goal of the research is answering this millennia-old question of life outside of earth. How many exoplanets are there? If they’re out there, are they potentially habitable?” said Angerhausen during one of our interviews, which took place in the car as we drove from Reno to Boise. “It’s an interface between philosophy and science. Larger questions are the ones that deeply touch me.”
The Rockstar (and Non-Rockstar) Life of an Astrophysicist
Angerhausen is from Cologne, Germany. The 40-year-old is a Center for Space and Habitability fellow at University of Bern; before that, he was a postdoc at NASA Goddard. He looks and acts nothing like a stereotypical scientist—more like a gonzo journalist drugging his way through the West. That’s the role I was supposed to be playing, as we made our way from San Francisco through Reno to Boise, and then to Weiser for totality. Our journey, however, was neither drug-fueled nor depraved. There were no accidents or coincidences or meltdowns. Scientists are not known for falling through cracks.
“Scientists seem to be insecure sometimes, because we are constantly thinking about not the worst-case scenarios, but what we are unsure about,” says Angerhausen. He rejects the stereotype of scientists as antisocial nerds, but he does acknowledge they are the sort of people who keep an eye toward Murphy’s Law. “We’re not thinking about the 99.9 percent we are sure about. We’re thinking about that .5 percent we’re not sure about.”
According to Angerhausen, being a professional astrophysicist is both more and less sexy than you might imagine. On the one hand, he travels the globe for speaking engagements in cool locations. He hangs out at places like NASA Ames — an old-school science campus in Mountain View, California, strewn with space shuttle parts and populated by beer-drinking rocket scientists. He’s flown on SOFIA, a 747 retrofitted with a telescope that travels to the edge of space.
“I’m surrounded by some of the smartest people in the world. Other people freak out when they see me: ‘Oh, oh, I’ve never met an astrophysicist!’ I sit with 15 astrophysicists every day at lunch. That’s always a privilege,” explains Angerhausen. “But, I mean, there’s a reason I’m 40 and still not married. I’ve moved 10, 12 times in the last 10 years, so it’s pretty hard to keep up. You always start a new life wherever you go.”
While Angerhausen lives a sort of science rockstar life, the practice of astronomy itself is quite boring. It’s not sweeping building-sized telescopes through the sky on a whim; it’s watching charts and graphs slowly make their way across a screen. Conferences like Exoclipse are brutally dull: nine unbroken hours of dry lectures, abstruse poster boards, and watery coffee. (I have never seen any group of people drink more coffee than scientists.) Even SOFIA, as Angerhausen puts it, combines two of the most tedious activities in existence: sitting on a plane and watching as data comes in from a telescope.
Written science is even worse. Many science journals exist only to provide scientists with citable bylines. In 2014, one particularly “predatory” journal, which charges eager scientists a fee for publication, published a paper titled “Get Me Off Your Fucking Mailing List,” which had supposedly been edited and peer reviewed. It goes to show that the vast majority of science discourse is being ignored, even by those responsible for disseminating it. It’s just too dense.
Angerhausen and I left San Francisco and drove 3.5 hours to Reno. On the way, we were surprised to learn that every hotel was booked. The “Biggest Little City in the World” was flooded with revelers on their way to the path of totality. We lucked into an online booking of the last room at the utterly depressing Reno Travelodge and arrived in the midst of a frantic queue. Some people with online reservations were turned away due to overbooking. In the decrepit double, we watched local TV advertisements for Denny’s one-day-only Mooncakes.
Fearing nightmarish traffic, we got up at six and hit the road. We stopped to pee at the “Welcome to Idaho” sign. A blanket of pale grasshoppers bounced from the brown grass onto the asphalt. Several cars full of eclipse revelers were gathered there, taking photos at the sign. A hipster from San Francisco named Cornelius wielded an old-timey accordion Polaroid. The back of his car had a bumper sticker that read “Shoot Film.” He was leading a caravan to a friend’s family ranch in Midvale, where they would camp and achieve totality.
We continued on the one-lane highway, passing where we could. The landscape outside Boise is mustard yellow and dark gray painted over short, blunt hills. It is strikingly not striking. Its vistas are as utilitarian as the potatoes they produce.
Every affordable hotel room in Boise had been booked for months, but Angerhausen had a pullout couch in his Marriott suite provided by the conference. To assuage my nervousness about the next morning, I rented a cruiser bike from the hotel and took a ride along the beautiful but crowded Boise River. Boiseans bobbed downstream in blow-up rafts. On a tiny river beach, a line of wet-shirted Christians ran into the river, where a man was holding people’s noses and dunking them backwards into the water. An audience watched from a bridge above.
The plan was to wake up at four a.m. to catch a bus organized by the conference. A lot was still up in the air. Traffic times had been estimated at six to 10 hours, as the small town of Weiser (pronounced Weezer), population 5,500, was declared by the Idaho Statesman to be expecting as many as 100,000 people.
There was also the dreaded possibility of being “clouded out,” which had ruined Angerhausen’s only other attempt at witnessing totality. That night, he dreamed that we got stuck in a tunnel on the way to Weiser and missed it entirely.
I tossed and turned for the few hours until four. We made it to the bus and departed promptly at five. On the way, excited scientists alternatively chirped predictions, refreshed their Star Chart apps for ingress/egress updates, and fell asleep. Gavin Coleman, a witty British astronomer and Angerhausen’s colleague at the University of Bern, pointed out Venus, which was prominent in the morning dark, the only thing visible above the yellow silhouettes of the hills.
Twenty minutes outside Weiser, the sun began to rise. We had faced no traffic and were more than five hours early. Even at six a.m., vendors were already out with homemade signs selling eclipse T-shirts.
We had made it, and now the only uncertainties were scientific. Would there be a “moonrise,” where the moon is visible as it approaches the sun? Or maybe a “shadow of totality,” a sort of apocalyptic shadow line sweeping the earth like the blast radius of a nuke?
In the parking lot of Weiser High School, traffic volunteers in neon vests scurried through the dawn. Every available space was thick with campers, many with people still asleep in their front seats. On some far hills, a pair of two-story sculptures shaped like spiders became visible, the husks of old cars for bodies.
Weiser is a small, run-down town with four churches on its main drag alone. Even this early, there was some tension in the air as tourists mixed with locals. Hipsters in straw hats were glared at from passing pickups. A gay couple held hands in apparent defiance. On the street, an urbanite admonished an obese old man who blew a stop sign in his old Ford.
We stood outside a coffee shop in line that ran almost around a corner. Pale geeks speaking French and German contrasted sharply with the cowboy milieu of Weiser’s diluted urban core. On a bench outside the coffee shop, a tattooed local sat with a gun strapped to the outside of his jeans.
“Honestly, it’s been a godsend to this town after the winter we’ve had,” he said to a friend. I asked what he meant. “One of the worst winters in 40 years here. Over four feet of snow.” He didn’t say “So much for global warming,” but the pit of awkward silence between him and the scientists said much more.
Finally, the eclipse began. I put on my cardboard eclipse glasses designed to block 99.999 percent of the sun’s light — another way science enables sight through obscurity — and raised my head toward the sky. All I could see was a white dot with another dot slowly moving over it—not very exciting, but as we continued toward totality, the light began to change and the world around us took on a surreal character. The light became a heavy yellow, then red. Watchers pierced pinholes in cardboard gum containers and projected the slivered sun onto their picnic blankets. They held up their fingers to make tiny pinhole cameras, projecting slivers onto the ground. The reflections through the leaves began to appear in crescents, as did the light flares on my digital camera. The science behind this phenomenon, that every glimmer of light is somehow dictated by the geometry of the sun, is mind-boggling. If we had two suns, we would have two shadows.
The temperature dropped rapidly. Where it had been unbearably hot a few minutes ago, now it was now a dusky golden hour. Even though just a tiny sliver of sun was visible through the goggles, there was still so much light in the world. In the moment of totality, the sliver morphed into a flaming ring, and I felt a satisfying click in my brain, something like sinking the eight ball into a corner pocket. I could look at it easily without the goggles, and seeing it naked produced a strange sensation of almost postcoital satisfaction.
A roar of cheers erupted across Weiser. Some scientists pumped their fists; others stood silent with mouths wide open. It wasn’t nighttime dark, but close. The sky seemed to hang like heavy purple luggage almost but not quite all the way down to the horizon.
The moon was invisible on the rise and the lights went out like on a dimmer. Not a tsunami of black, but the scientists didn’t seem disappointed. They were ruddy and giggly, like a football team after a big win.
And then, suddenly, it was daylight again and everything went back to normal, like turning on the lights after watching a movie. It happened quickly, much faster, it seemed, than the drawn out arrival of darkness. The heat rose back to unbearable. The vast majority of watchers—many of whom had, like us, traveled days to get here—were already packing up to go, long before the moon would relinquish its grip.
Angerhausen, a satisfied smirk on his face, looked at the exodus and shrugged.
“Nobody ever sees the end of a solar eclipse,” he said.
Yearning for the Red Edge
There’s one final reason why eclipses are so important to astronomers. As Angerhausen explains, exoplanets are important because they could harbor alien life or support human life. This is where something called the “red edge” comes in.
Plants emit a uniquely large amount of infrared light, which has major implications in the search for life on exoplanets. “If you look at Earth from an orbiting satellite, we have huge amount of vegetation on the surface, and you’ll actually see a unique signature in the reflected spectrum,” says Avi Mandell, a research scientist at NASA’s Goddard Space Flight Center who was in Boise for Exoclipse and witnessed totality in Weiser. “This is one of the things that people call an absolute slam dunk for detecting biology on exoplanets.”
In other words, if aliens with our current technology viewed Earth, they could be reasonably certain that there is life here because of a noticeable uptick in the infrared light emanating from our planet’s vegetation. This increase is called the red edge.
If a red edge is discovered, “it would be immense,” says Mandell. “It’d probably be the clearest signal of extant biology on another planet, because there’s no other way we can think of to create that effect.”
Unfortunately, red edges cannot be discovered through transit photometry. They can only be seen using a newer, more difficult method called direct imaging. The first time we observed light from an exoplanet using this method — actually seeing an exoplanet for the first time — was the discovery of 2M1207b in 2015.
Using direct imaging to test for the red edge requires, essentially, an artificial eclipse. To see exoplanets’ light, the light of their stars must first be obscured, which is how 2M1207b was finally discovered. Infrared exoplanet telescopes—like NASA’s new WFIRST, set to launch in the mid-2020s—create their own artificial solar eclipses inside the telescopes themselves. They use a disk, called a coronagraph, to block out the star, somewhat like putting your finger over the flash of a camera.
To astronomers, the importance of the 2017 eclipse revolved around a similar mechanism—the opportunity that arises from shadowed stars. Oftentimes, our chief hurdle in understanding the universe isn’t that we can’t see distant worlds, but that we can see too much of them. Only during eclipses, real and artificial, can we reduce brightness enough to begin the next chapter in our hunt for habitable planets and alien life.