Our public open house for the Transit of Venus was surprising for a few different reasons. First, we had clear skies! Usually, when we plan a public observing events, that’s the signal for clouds to rush in from all directions and hover over the Paul Tebbe Observatory. Our second surprise after having clear skies was to have hundreds of people lined up to take a look at the Sun and Venus! Normally, we have a 50 or so people turn out for one of our events. For this past Spring’s Evening With The Stars program, we were elated to have 150 people come out. This past Tuesday, we EASILY had double that number if not more! People from the college and the community lined up down the stairwell from the roof and all the way down the hall on the 4th floor of the CLB, and all evening long, the line never shrank!
We apologize to those who weren’t able to make it to the roof before sunset, but for those who did, we got to see a fantastic and rare sight, Venus eclipsing the Sun! Venus is nearly as large as the Earth, and nearly four times the size of our Moon, but since it’s much further away from us, it’s angular size in the sky is much smaller than the Moon’s so when Venus passed directly between us and the Sun, it didn’t block the entire disc of the Sun, but only a part of it. Since Venus doesn’t orbit in precisely the same plane around the Sun as the Earth, it’s very rare that Venus ever passes directly between us and the Sun. Usually, Venus misses the Sun by a degree or two, but when the geometry is just right, we’re treated to a transit event like we were able to witness last Tuesday evening.
The dark disc of Venus passing across the face of the Sun wasn’t the only thing that visitors were able to see when they came to the Paul Tebbe Observatory. With the two different types of filters we were using to observe the Sun, we were able to see a number of sunspots, and some solar prominences, hydrogen and helium gas caught up in large magnetic arcs above the solar surface. After sunset, many stayed around and were able to see Mars and Saturn through the telescopes as well as the double-star Alberio.
All in all, it was a fantastic evening and we were overwhelmed and humbled by the magnitude of the turnout. We would like to thank everyone who came out to join us and look forward to our next observing event! To see more photos from the event, check out our page on Facebook.
Learn more about the history of planetary transits, and about this year’s transit of Venus at http://www.transitofvenus.org/.