David A. Aguilar and Jay M. Pasachoff discuss June 8th, 2004, when we on Earth will witness Venus passing in front of the Sun for the first time in 122 years. This phenomenon, known as the transit of Venus, is one of the rarest of planetary alignments. The transit lasts about 6 hours and is visible from most of Europe, Africa, and Asia though, similar to an eclipse, it cannot be witnessed without a sun filter. Observations of the transit were used in the 18th and 19th centuries to determine the size of the solar system. That method has since been dismissed for its impracticality, but the transit will provide much opportunity to develop and test new techniques for the study of planets outside our solar system.
A naturalist, astronomer, author, and artist, David's expertise is in communicating the wonderment of science. He is the past Director of the Fiske Planetarium & Science Center and the originator of the Science Discovery Program at the University of Colorado in Boulder, Marketing Communications Director at Ball Aerospace and Technologies Corporation, and Marketing Director for PBS's Emmy-winning NOVA series, *Evolution*. He is also a recognized writer and space artist with work appearing in the new 2008 BBC television series *UNIVERSE*, *Time magazine*, *US News & World Report*, *ABC Nightly News*, CNN, *NY Times*, *USA Today*, *National Geographic*, *Sky & Telescope, Astronomy, and Scientific American*. He is the author and illustrator of *Planets, Stars & Galaxies and The New Solar System*, published by *National Geographic*, as well as a scholar lecturer on Smithsonian World Tours and Smithsonian Journeys, and popular host of the Harvard-Smithsonian Center for Astrophysics programs *Observatory Nights* and the Harvard Lecture Series, *Everything I Learned About Science I Learned At The Movies*. He is also an avid telescope maker and an astronomical and underwater photographer.
Jay M. Pasachoff specializes in studying the sun at total solar eclipses, working closely with Dr. Steven Souza and Dr. Bryce Babcock. They carry out experiments to study the million-degree-temperature of the solar corona in order to find out how the corona gets so hot. Their work has been supported by the National Geographic Society, the National Science Foundation, and the Keck Northeast Astronomy Consortium. Dr. Pasachoff, along with Dr. Souza, and Dr. Babcock carried out an extensive expedition to Kastellorizo, in the Greek Dodecanese islands, for the March 29, 2006, total solar eclipse. They included a half dozen astrophysics and astronomy majors. Dr. Pasachoff and Babcock had a similar expedition to Siberia for the August 1, 2008, total solar eclipse. They are now planning an expedition for the July 22, 2009, total solar eclipse in China.