Highlighted Team Member
S. Peale, Science Team Co-Investigator

S. Peale can't remember a time when he wasn't interested in the planets and gardening.

"I was raised poor in Indiana, and my family - by necessity - had a garden every summer," explains Peale, a Professor Emeritus and Research Professor of Physics at the University of California, Santa Barbara. "When I was 12, I worked on a truck garden south of Indianapolis. Truck gardens get their name from the fact that farmers who owned them hauled their produce to market in trucks. Each day, they would call up the place where they sold and ask them what they need, and haul it there."

Since then, he's always enjoyed raising things to eat, particularly things he could not buy in the run of the mill grocery store. "Tomatoes have always been my favorite," he says. "But I have raised tomatoes too many times in the same place, and they no longer grow well, probably because of a root parasite. Also, Santa Barbara now has a number of fine farmer's markets where you can purchase the most magnificent tomatoes. So the things that once motivated me [to garden] are no longer an issue."

He still tinkers around in the yard on Saturdays, he says. But much of his time is spent focusing on celestial bodies, specifically what moves them. Peale is a leading expert in planetary dynamics. He developed the technique by which MESSENGER can measure the state of Mercury's core. He will participate in the interpretation of the data defining the constraints on Mercury's rotation from the Mercury Laser Altimeter (MLA) and the gravitational field.

His interest in planets also dates back to his youth. "I remember being fascinated as a kid with the planets, and reading about them in this set of encyclopedias we used to have," he says.

He was a graduate student at Cornell in the early 1960s, when William E. Gordon, a professor of electrical engineering at Cornell University, realized his dream of building an instrument that would use radar to study the ionosphere, the uppermost region of the Earth's atmosphere, as well as objects in the solar system. It was the radar study of the planets that captured Peale's interest.

"I had just finished my master's when they announced that Gordon's Arecibo radar was going online," he said. "They said it was going to reveal lots of secrets about the planets, their surfaces. It seemed so exciting and romantic at the time. If Marshall Cohen had not gone on sabbatical leave when I was choosing an advisor, I would have become a radar astronomer."

Peale went on to pursue a Ph.D. in planetary physics and is well-known for his contributions to the dynamics of solar-system bodies, especially for calculations leading to the prediction of volcanic action on Io, dramatically verified by Voyager photography.

Aside from his work on MESSENGER, Peale is dabbling in other research projects, such as the dynamics and origin of extra solar planetary systems and the origin and evolution of multi-planet and multi-satellite systems where their orbital periods are in ratios of small whole numbers. Examples of the latter are the 3:4 resonance for Saturn's satellites Titan and Hyperion and the 1:2:4 resonance for Jupiter's satellites Io, Europa, and Ganymede.

He's been published in several journals and been honored with prestigious awards such as the American Astronomical Society's Dick Brower Award and being named a fellow of the American Geophysical Union. In 1982, he even had an asteroid named after him. Still, he says, he wishes he were smarter.

"There are innumerable things I want to look into, but it takes so long to do so," he says. "I've always wished that I could cull ideas much more rapidly than I do."

By: P. Campbell, Johns Hopkins University Applied Physics Laboratory