At 92 years of age, Fred Whipple, the noted Harvard astronomer who fathered the phrase "dirty snowball" to describe comets, has been named to serve on a NASA space mission team. He is joining the agency's Comet Nucleus Tour (Contour), scheduled for launch in 2002.

Whipple is the oldest researcher ever to accept an active role in a NASA space science mission. Previously, the oldest researcher known to actively work on a NASA mission was James Van Allen, the physicist who discovered the Van Allen belts, who worked on the Galileo Mission to Jupiter at the age of 83.

Until a few years ago, Whipple rode his bicycle three miles from his home to work. And yesterday (Sunday) he attended his first meeting of the Contour science team at Cornell University, and he has let it be known he expects to attend every team meeting.

"Fred is the most venerable cometary scientist in the world," says Joseph F. Veverka, Cornell professor of astronomy and the principal scientific investigator on the comet mission. "He will add a reservoir of wisdom and experience to the Contour team. There isn't a scientist working this field who is unaware of Whipple's work in the study of comets."

The fantastic, robotic Contour voyage will visit comets Encke, Schwassmann-Wachmann 3 and d'Arrest. The unmanned mission will take images and comparative spectral maps of cometary nuclei and analyze the dust and gas flowing from them. In 1997, Cornell was awarded $154 millon to conduct the mission, the largest single mission grant in the school's 129-year history.

As a student at Occidental College in California, Whipple worked as a store clerk who accompanied customers as they made buying decisions and added up their purchases in his head. Armed with this mathematical talent, Whipple became a math major and then later earned his undergraduate degree at the University of California at Los Angeles. He was awarded his doctoral degree in astronomy by the University of California at Berkeley.

Whipple then headed east to Harvard, where his first job was to inspect sky survey photographic plates, making sure the telescopic camera was accurate. To alleviate the tedium, Whipple looked for comets in the photographic negatives. He found six.

Whipple's research on comets set the astronomical world on its axis. In March 1950, in a seminal paper on comet nuclei published in the Astrophysical Journal, Whipple theorized that the gases comets pour out as they travel around the sun come from the icy shroud of the cometary nucleus. Solar rays heat the water ice, releasing the water as gas. This so-called gas gives comet watchers on Earth views of beautiful, sweeping comet tails. Because of the water ice and other cosmic debris packed into a comet, Whipple coined the term "dirty snowball."

In 1955, Whipple became the director of the Smithsonian Astrophysical Observatory (SAO), in a small headquarters behind the Smithsonian Castle in Washington, D.C., and helped move the SAO to its present location in Cambridge, Mass. Today, the SAO is part of the Harvard-Smithsonian Center for Astrophysics, and the center's Fred Lawrence Whipple Observatory in Amado, Ariz., bears his name.

Whipple has crossed career paths with many astronomical giants. He was the first man to hire a young Carl Sagan for the faculty at Harvard, before Sagan joined the Cornell faculty. And Veverka, the chair of Cornell's astronomy department, was Whipple's last graduate student at Harvard.

EDITORS: On Wednesday, July 28, at 2 p.m., in the Auditorium at the Statler Hall on the Cornell University campus, Fred Whipple will be presented with a framed picture designed by Mary Anderson and Margaret Morris at the Applied Physics Laboratory (APL) at Johns Hopkins University. The picture, signed by the 22 researchers on the Contour team, depicts Whipple and a reproduction of the title page of his seminal paper on comet nuclei published in the Astrophysical Journal of March 1950. You are invited to cover the ceremony, which takes place during the Comets, Meteors and Asteroids Conference, being held at Cornell throughout this week. The presentation will be a surprise to Whipple, so please do not mention it until he receives it.