Legos and Lasers

Photo by Robert Peck.

Yale’s optics laboratory is spotless. Anyone who enters must don a hairnet, shoe covers, and a lab coat (preferably white). A jumble of optic wiring emits an eerie green glow as concentrated light leaks out through small breaks in the line like slime. Complex instruments perch atop tables, daring observers to approach them and upset their delicate balance.

This lab is Zachary Kaplan ’13’s playroom. He uses it to fine-tune technology that can determine details about planets far beyond the bounds of our solar system.

“I like to compare this to building Lego sets,” Kaplan says, “except with lasers.”

Kaplan is part of an elite Yale program that hunts for planets outside our solar system using some of today’s most advanced equipment. Founded by veteran planet hunter Debra Fischer, the Yale Exoplanet Group has facilitated the discovery of numerous planets. Since she began her work in 1997, Fischer herself has co-discovered several hundred.

“In those early days,” Fischer says, “it was easy to point to ‘the most significant’ find.” Nowadays, however, she admits that she’s stopped keeping track of the exact number of worlds she’s found in the sky.

As small as they are, planets outside the solar system can’t be seen directly, even with modern equipment. Fischer, Kaplan, and other night-sky explorers like them have to search for planets with a different method: they look to stars that are influenced ever so slightly by the pull of planets orbiting around them. The planets’ gravity makes these stars “wobble” back and forth just enough that, with sensitive equipment, the Exoplanet Group can pinpoint exactly where the planets are. This kind of observation requires instruments that can detect movement of just a few meters from hundreds of millions of miles away. Such instruments are rare, and at most institutions, researchers can’t even see the equipment until they’re enrolled in graduate school.

At Yale, undergrads can spend time in the lab themselves, working on problems alongside senior faculty members in a way that Fischer describes as “quite unique” among planet-hunting groups worldwide. Though Fischer’s exoplanet lab sees its share of graduate student activity, there are just as many undergraduates working there. Some go when they can; some go every night.

Kaplan has accumulated enough course credit through Yale’s accelerated graduation program that he has enough time this spring to work in the lab full-time. His focus is astronomical technology: in February, he traveled to Chile to help fine-tune a new instrument designed to seek out extrasolar planets the size of Earth, which could hold the key to discovering life beyond our solar system. So far, current technology can’t detect a planet that small, but Kaplan’s work, along with that of many other experts, could help to change that. Though he’s decades younger than many of his peers, Kaplan has already co-authored two journal papers and a chapter of a book about optics in astronomy.

Another undergrad, Charlie Sharzer ’12, is essentially searching for Star Wars’ forest moon of Endor. Sharzer’s work focuses not on extrasolar planets, but the moons that orbit them. By observing the large planets’ orbits, Sharzer hopes to find a moon within the so-called “goldilocks zone”: an area with temperatures not too hot and not too cold, perfect for sustaining life. So far, no extrasolar moons have been found, meaning that Sharzer’s research is some of the first of its kind. Since he works independently of his professors and peers, his research comes with some risks — something that Sharzer is well aware of.

“If I come up with a lot of captures in my simulations, that would raise a lot of enthusiasm in the study of exomoons,” Sharzer said. “But since I have little experience and I’m not explicitly working for a professor, there’s also the possibility that I’m doing everything wrong.”

Fischer, Sharzer, Kaplan, and the rest of Yale’s team are intent on making one ultimate discovery: finding planets outside our solar system that could support life. It’s that goal that drives Kaplan and Sharzer to spend long hours in the lab every week on top of their other activities. Getting started so early on their planet-hunting careers makes it more likely that they’ll eventually find what they are looking for. If it’s even there.