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People: Peter Tenenbaum—Eyes on the Sky

(Photo - Peter Tenenbaum)
SLAC accelerator physicist Peter Tenenbaum at the NASA Ames Research Center. (Photo courtesy of Peter Tenenbaum. Click for larger image.)

"In science fiction—while the details differ—there are usually other star systems that look like ours: they have Earth-like inner planets and big outer planets. And so far, we have no idea if that's even vaguely true," said SLAC accelerator physicist Peter Tenenbaum. "But in a few years we will know."

That information will be collected by NASA's Kepler mission, launched last month. Kepler is the first space mission dedicated solely to finding and studying solar systems outside our own. "I don't think I can convey in words how exciting that is," Tenenbaum said, "knowing something that big about the universe."

Tenenbaum doesn't just talk about this exciting search for extra-solar planets; he's working on it. In January of 2008, Tenenbaum was working at SLAC on the design of the International Linear Collider when he happened to read about an opening for scientific programmers to work on the Kepler mission. Enthusiastic about the fascinating science that Kepler would address, Tenenbaum took a leave of absence from SLAC to join a team at the NASA Ames Research Center in Sunnyvale, designing software for the mission.

"What I'm doing here is very similar to what I'm used to," he said. Commissioning an accelerator and commissioning a spacecraft are very similar experiences." Tenenbaum said his training as an accelerator physicist, which included writing software and handling very large amounts of data, prepared him quite well for his work with Kepler. "In the modern era, the physical sciences are inextricably, irredeemably tied up with software development. There's no way around that. We are doing science processing in Matlab and I had become an extremely capable Matlab user during my time at SLAC."

To help detect the presence of far-away planets, the Kepler team was called upon to detect a change in a star's brightness of only 100 parts per million. Tenenbaum said he immediately recalled needing to measure the position of an electron beam to one micron in a two centimeter diameter beamtube, which was part of his PhD thesis. "You can think about the requirements in the same way," he said. "You know what it took to achieve that precision, and what degree of difficulty that implies for this space science mission."

On March 6 of this year, Tenenbaum joined many of Kepler's team members at Cape Canaveral for the launch.

"I had never seen [a launch]," he said. "It was an incredible experience, thinking about this thing we all worked so hard on and watching it all go up. Watching it all start."

The Kepler spacecraft is now coasting away from Earth, and is being prepared for science data collection. While the lens of the Kepler's science instrument, called a photometer, is covered, the Kepler team is performing calibrations. Once the photometer is uncovered, a few more weeks of commissioning activities will take place before the first science data are taken. Then—as early as next month—Kepler's search for Earth-like planets can begin in earnest.

"I was attracted to the [Kepler] position because the science is so compelling. You get into science because you want answers and you want to be a part of how the answer was arrived at and know what it means," he said. "Being a part of building that knowledge little by little, and year by year—that's just awesome."

—Calla Cofield
SLAC Today, April 7, 2009