An international meeting of astronomers this summer will feature a talk by Jim Bell, Cornell professor of astronomy, who will give one of four invited discourses at the conference.

Bell, who leads the Pancam team for NASA's Mars Exploration Rover mission -- now in its sixth year -- will give a talk titled "Water on Planets" at the International Astronomical Union's general assembly, Aug. 3-14 in Rio de Janeiro, Brazil.

Bell's talk will review the origin, distribution and evolution of water in our solar system and in others, as well as the data available on distribution and abundance of water on planetary bodies.

He will also address questions that still plague scientists: Where did Earth's water come from? How much water did, or does, Mars have? What happened to Venus' water? Does ice exist in unlikely places like the poles of the moon and Mercury, and do oceans exist on outer solar system satellites?

"These kinds of mysteries continue to guide our search for water in our solar system and beyond," Bell says.