ECLIPSE VIEWING GLASSES: Those who plan to view the transit of Venus should take the same precautions as those used to view a partial eclipse of the sun.

On the evening of Tuesday, June 5, North American observers will have an opportunity to see something that won’t occur again in their lifetimes: the transit of Venus across the sun. To mark the occasion, Princeton University’s Astrophysics Department is holding an open house that will begin at 4 p.m. at Peyton Hall, on Ivy Lane. Members of The Amateur Astronomers Association of Princeton will also be present.

There is no charge for the program, which is open to all ages and will include a talk about transits, as well as “hands-on activities for young and old alike.” At around 5:30 p.m. participants will walk from Peyton Hall to the roof of the E-quad (Engineering faculty) parking lot on Olden Lane, where there will be telescopes set up to view the transit, which will begin just after 6 p.m.

“We will watch it for as long as we can until the sun goes down (at 8:22 p.m.), after which we will screen the transit from a more western location,” said a Department spokesperson, who encouraged everyone to “come by for an interesting afternoon of physics and astronomy.”

A transit occurs when Venus passes directly between the earth and the sun, and the distant planet can be seen as a small dot gliding slowly across the face of the sun. Transits of Venus occur in pairs that are eight years apart and then don’t happen again for more than a century. Prior to the current pair (the first of which occurred in 2004), the last two Venus transits were in 1874 and 1882. After the transit in 2012, there won’t be another pair until 2117 and 2125.

A website, www.transitof
venus.org, offers more information about the phenomenon. In earlier centuries it was believed to offer unique opportunities for scientific research. In 1761, for example, scientists travelled to far corners of the earth in anticipation of the June 6 transit to collect data they believed would help to calculate the size of the solar system.

A new book about that episode, Chasing Venus: The Race to Measure the Heavens, by Andrea Wulf, has been published by Knopf just in time for this year’s transit. A less-than-enthusiastic review of the book in the New York Times last weekend, however, concluded by suggesting that “dabblers might do better to sit quietly during this year’s transit and simply watch the goddess’s stately progress.” Princeton’s Astrophysics Department’s invitation sounds like a good one. Updates on their June 5 program will appear at www.princeton.edu/astro/resources/outreach/venus-transit-2012/.

And, for a more promising read, perhaps, the Princeton Public Library has a copy of Shirley Hazzard’s novel, The Transit of Venus, which elicited cosmic words like “iridescent” and “luminous” when it was published in 1990.