The Transit of Venus: Coming to a Sky Near You!

By now, you’ve most likely heard the buzz about the Transit of Venus, occurring Tuesday, June 5, 2012. This cosmic event is worthy of all the attention it has received this week – after all, it only happens every 105.5 or 121.5 years. During the transit, the shadow of Venus will be visible against the sun as it makes its way across its orbital path (much like a mobile, solar beauty mark).
Here’s an informative video that explains why the Transit of Venus is particularly elusive:

Hundreds of observatories across the globe are opening up their doors for public viewings of the transit so that the public can bear witness to this rare astral occurrence, including the Adler Planetarium in Chicago, IL which will host a public viewing night. They’ll even provide telescopes to facilitate safe viewing of the transit.
In Philadelphia, the Transit is scheduled to start at 6:03pm and the Franklin Institute will open its door for a viewing party starting at 4:30 with guests lectures. Also in Philadelphia, check out a special exhibit marking the occasion at the American Philosophical Society.
Perhaps there’s an observatory near you hosting a similar event! Even if there isn’t, here are some tips on how to safely view this event. And here’s a handy list of the global viewing times. Another good way to view the transit is to live stream it from starting at 3pm PT/6pm ET.

The quintessential reason that the Transit of Venus was so important is that it helped astronomers determine the distance between the Earth and the sun. Johannes Kepler first posited that by calculating this distance, it would then be possible to determine the distance between Earth and other objects – stars, moons, other planets, and eventually galaxies. Before that could happen, though, one would need to calculate the distance between earth and one planet.

Venus transits in particular, with a little help from trigonometry, can be triangulated from different points on the globe in order to determine its distance from our planet. The first time this happened on a collaborative scale was in 1761. That year, dozens of teams around the globe promulgated a massive effort to jointly track the transit that year. (Though Edmund Halley never lived to see this effort, he had exhorted generations of scientists that would supersede him to engage in such an opportunity.) As BBC’s Tom Feilden put it, “Countries…that were at war had to collaborate with each other…hundreds of astronomers looked at the sky at the same time for 6 hours and measured this astronomical event…”

The Transit of Venus comes with a long history, and its enduring legacy helped initiate the movement of modern, collaborative science. This Tuesday, you can participate in true collaborative fashion by observing the skies along with millions of others around the globe and sharing your observations using this free Transit of Venus Smart Phone App!
Unless you plan on cryogenically preserving yourself until the year 2117 (when the next Transit of Venus will occur), don’t miss it this time around!

Categories: Astronomy & Space, Citizen Science

About the Author


Lily Bui

Although she holds dual non-science bachelors’ degrees in International Studies and Spanish from the University of California Irvine, Lily has long harbored a proclivity for the sciences. A daughter of an engineer and an accountant who also happen to be a photographer and musician, respectively, Lily grew up on the nexus between science and art. Lily has worked on Capitol Hill in Washington, D.C.; served a year in AmeriCorps in Montgomery County, Maryland; worked for a New York Times bestselling ghostwriter in California; and performed across the U.S. as a touring musician. She currently works with WGBH-TV Boston and Public Radio Exchange (PRX) in Cambridge. In her spare time, she thinks of cheesy science puns (mostly to entertain herself). // Tweets @dangerbui