June 7 is your chance to see this rare eclipse, when Chabot hosts a special evening event to highlight this historic crossing. You can see the transit broadcast live from Greece in the planetarium, beginning at about 9:45 p.m.

Before that, have fun making a solar wristwatch or sun model, go on a solar scavenger hunt or be part of another sun-Earth activity. You can also watch the BBC dramatization "Alas Poor Horrocks," the story of Jeremiah Horrocks, the man who first observed the Venus transit in 1639, and listen to Sousa's "Venus Transit March."

The telescopes will be open, weather permitting, as well as Chabot's current exhibits. Seating is limited and advance tickets are recommended.

The next transit of Venus occurs in 2012 -- and not again until 2134.

In 1882, astronomers around the world made expeditions to observe the transit, and then used their observations to measure distances to the sun and figure out the size of our solar system. They did this using telescopes, trigonometry, geometry, and parallax measurements.

Ben Burress, a Chabot astronomer and teacher, will be on-hand during the June 7 event to explain the complicated geometry behind such measurements and answer questions.

Although we may have romantic notions about the planet, it is a tough place to visit. The atmosphere is mainly composed of carbon dioxide, and the planet's rain contains sulfuric acid. The surface temperature is over 800 degrees. And the atmosphere is so dense that the pressure would crush you by a half-ton per square inch.

"We are now on the eve of the second transit of a pair, after which there will be no other till the twenty-first century of our era has dawned upon the earth, and the June flowers are blooming in 2004," wrote William Harkness, an astronomer who observed the 1882 transit.

"When the last transit season occurred the intellectual world was awakening from the slumber of ages, and that wondrous scientific activity which has led to our present advanced knowledge was just beginning," Harkness continued. "What will be the state of science when the next transit season arrives, God only knows. Not even our children's children will live to take part in the astronomy of that day. As for ourselves, we have to do with the present . . . "

Reach Judyth Collin, Marketing Coordinator, Chabot Space & Science Center, at (510) 336-7310 or jcollin@chabotspace.org.

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