Bill Borucki's Planet Search
Finding another Earth may be easier than the Kepler project's long quest for funding.
- By Andrew Lawler
- Air & Space magazine, May 2003
(Page 2 of 6)
Sweat and Zeal
Borucki’s single-minded zeal is as clear as his youthful blue eyes. Born in Chicago in 1939, he grew up in Delavan, Wisconsin, “between Yerkes Observatory and the Playboy Club on Lake Geneva,” and expressed interest in astronomical matters early on. While in his teens, the town sheriff would close off roads so that Borucki and his buddies could launch 10-foot multi-stage rockets. Borucki’s father, an inspector at a clock factory, procured timing mechanisms for them.
In 1962, a year after President Kennedy challenged the Soviets to a moon race, Borucki, fresh from a physics degree at the University of Wisconsin at Madison, landed at Ames, where he studied the effects of radiation on reentry vehicles—work that was used to design Apollo heat shields. But what ultimately fired his passion was the possibility of discovering other worlds.
He was in the right place. In the 1970s Ames hosted a session on space colonization, and it also was the home of NASA’s Search for Extraterrestrial Intelligence. Borucki got to know many of SETI’s legendary figures, including Carl Sagan and Jill Tarter.
In the summer of 1982, Borucki looked in on an Ames conference on extrasolar planets, a far-out topic at the time. Transit photometry was mentioned only in passing because detectors of the day simply couldn’t measure stellar variability to the degree necessary. “We needed precision of one or two parts in a hundred thousand, and no one knew how to get there,” he recalls.
The idea of transit photometry wasn’t new. Astronomer Frank Rosenblatt speculated in a 1971 paper that the method could prove a valuable tool, but he died shortly thereafter.
Borucki picked up the thread and became increasingly intrigued—some would say infatuated—with the possibilities. He published a couple of papers on the subject, and in 1984, he somehow persuaded the director of Ames to fork over enough money from his discretionary purse to fund a small conference on the subject.
Roughly 20 astronomers attended the meeting, held in San Diego, and decided that it was theoretically possible to build such detectors. Scientists at the federal National Bureau of Standards suggested silicon diodes as quantum-perfect detectors—devices that would spit out a single electron for every photon of light absorbed. For three years Ames’ director used his discretionary fund to pay for Borucki’s development of silicon diode detectors, but Ames managers questioned how well the detectors would operate in space and remained skeptical.
In the late 1980s, Borucki’s team began to look at charge-coupled devices—technology more familiar to the astronomical community. Unlike silicon diodes, which can monitor only one star at a time, CCDs are array detectors that can survey thousands of stars simultaneously and are ideal for digital data gathering. Borucki had tested CCDs years before and had been disappointed with their degree of precision, but his team determined that newer CCDs were capable of the precision necessary to detect minuscule brightness changes. Though they’d never be as precise as silicon diodes, Borucki chose to go with CCDs for credibility.