Dozens of astronomers, physicists and engineers came together for a symposium July 28-29 at Cornell to celebrate the 65th birthday of Joe Burns, the Irving Porter Church Professor of Engineering, a professor of astronomy and a vice provost for research.

At the symposium, called "From Dust to Planets," Burns' colleagues and former graduate students spoke on topics ranging from planetary ring systems and the neuromechanics of swimming in lampreys to the experience of earning a Ph.D. under Burns' demanding but always good-humored guidance.

"It's too infrequent that we get a chance to say thank you publicly for people who have impacted our lives," said former graduate student Bob Kolvoord, a professor now at James Madison University. "And I think for all of his students he has done that. He showed us the importance of trust and high expectations, the virtue of diligence and hard work. He modeled hard work by example."

For Burns, the two-day event was a look back at 40 years' work in planetary science and celestial mechanics. "The excitement of exploring the solar system -- it's not something everybody gets to do," he said.

But the symposium was a brief pause, not an endpoint, in Burns' career.

Currently at work on NASA's Cassini mission studying Saturn's ring system, Burns and colleague Jeffrey Cuzzi wrote a recent article in Science summing up the mission's progress so far and its potential for the coming years.

With Cassini, Burns said, scientists are learning about the processes that form planetary rings and applying that knowledge to the study of how solar systems form from protoplanetary disks. "Dynamically, the processes are very similar," Burns said; both involve small pieces of matter orbiting a central mass, with collisions and gravitational and tidal forces affecting their behavior.

In its two years orbiting the ringed planet, Cassini has provided spectacular images -- resolved to just 100 meters -- and a wealth of new information.

The mission is slated to end in 2008, but Burns and others are recommending the mission be extended for up to four more years. That would allow astronomers to watch how the rings are affected as the sun crosses the ring plane in 2009 and begins warming their northern side. "We expect that dust susceptible to solar radiation will change sides. But is that going to happen? We don't know. It would be nice to see," he said.

Also later that year, the shepherd moon Prometheus will penetrate the rings, and in 2010, the satellite moons Janus and Epimetheus will switch positions, causing new waves to form near them in the rings, giving researchers a chance to study that process in detail.

At the symposium, the focus was also on Burns' lighter side. There was talk of the sandals he wears every day (even, according to legend, at a Christmas party at a U.S. embassy in a very northern climate), and his meticulous standards as 20-year editor of the journal Icarus.

Kolvoord spoke of the breadth and depth of Burns' research, resulting in hundreds of publications in journals from Science, Nature and Icarus to a piece on environmental art (co-authored with wife Judy) in the journal Leonardo.

French astronomer Andre Brahic reflected on his long friendship with Burns in an after-dinner speech in the Statler ballroom. And the colleagues who couldn't attend in person participated with written tributes.

"You have always done everything you do to the highest standards, even when insanely busy," wrote Richard Durisen, an Indiana University astronomer. "Joe, you are one of the shining examples of how to be a superb, creative and influential scientist and a warm human being at the same time."