Watching the transit of Venus

“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. 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. 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 . . .”  –  William Harkness, 1882 (from NASA/GSFC)

Tuesday was was the second of this century’s pair of transits of Venus; the first was the one referred to by William Harness, which occurred when the June flowers bloomed in 2004. I didn’t catch the 2004 transit, but I was fortunate to have a prime view of Tuesday’s. Like many others, I turned my eyes (safely behind sun filters) towards the Sun and the little black dot traversing its surface. Cutting edge technology also turned out to witness the event. The Hubble space telescope observed the transit of Venus, using the Moon as a mirror, trying to replicate the method that astronomers use to study the atmospheres of exoplanets. NASA’s Solar Dynamics Observatory captured the transit at multiple wavelengths, helping both to calibrate their instruments and to understand the oxygen content of Venus’ atmosphere. And astronaut Don Pettit photographed the event from the International Space Station.

With this transit complete, there won’t be another opportunity to see one from Earth until 2117. I wonder about the questions that will engage the scientific community when the next transit occurs – and whether future generations might observe a transit from another vantage point.

This time around though, most of us were Earth-bound. Those of us lucky to be on the right part of our planet and with good weather had the opportunity to witness this rare event. I asked the Astrobites authors to share their experiences with us.

Elisabeth Newton
Harvard University (Second year)I’m on Maui this week, attending a workshop on low mass stars. After three morning lectures, our group drove to the summit of Haleakala, a volcano that forms most of the island of Maui (Haleakala means “house of the sun” in Hawaiian). We arrived just in time for first contact. We watched the beginning of the transit through eclipse glasses, through cameras equipped with home-made mylar sun filters, in projection (left) and through the very nice telescopes set up by a team of amateur astronomers. There was quite a bit of excitement when we realized that some of our digital cameras could capture the transit through eclipse glasses (middle). After an hour of watching the transit, we walked to Haleakala crater, where Prof. John Stinton talked to us about the geology of the volcano. We spent most of the afternoon on a hike that took us into the crater, but made it back in time to watch the end of the transit. After third contact, during the final stages of the transit, I couldn’t see Venus by eye anymore, but I was able to watch until the very end by snapping photos every minute.
Courtney Dressing, Tanmoy Laskar, & Nathan Sanders
Harvard University (Second year, third year, and second year)

All three of us volunteer at the monthly public observing nights at the Center for Astrophysics in Cambridge, MA. We were even busier than usual yesterday evening when we invited all of Cambridge to join us for the transit of Venus. The skies were cloudy, but hundreds of people showed up to watch the webcast from Hawaii. Courtney also made transit of Venus cupcakes to share with the Solar, Stellar, and Planetary division at the Center for Astrophysics. Below from left to right: the crowds at the Center for Astrophysics, visitors watching the webcast, and transit of Venus cupcakes.

Chris Faesi, with Hope Chen, Ian Czekala, Kirit Karkare and Katherine Rosenfeld
Harvard University (first and second year)

We are all in attendance at the 13th Synthesis Imaging Workshop in Socorro and joined the NRAO-hosted Venus transit viewing at Etscorn Observatory on the New Mexico Tech Campus. There were no less than 6 small telescopes set up with filters, a handful more with projecting screens, and the big telescope with a camera attached. A sizable crowd, undeterred by the 95-degree sweltering heat, turned out for ingress, which officially began around 4:10. I first saw the second planet about halfway through ingress on a small, 6-inch reflector equipped with a solar filter. I immediately donned my super-heavy-duty solar shades (approved for eclipse use!) and squinted at our star, glancing at the upper left where I had seen the dark smudge of Venus begin to eat in to the Sun’s limb in the telescope eyepiece. Then I remembered that telescope optics exist, and looked in the proper place – the upper right. I still didn’t see it. I wandered a bit more, and peered through another small telescope that had an H-alpha filter. Unsurprisingly, it was very red (6563 angstroms, I believe), but I was astounded to see solar prominences snaking from the surface so clearly. Soon, the planet had completed ingress, and I decided to try for another look with my own eyes…but was still foiled. I just couldn’t see it. Then I remembered another piece of important optics – I wear glasses! Soon I had them on underneath the solar shades, and sure enough, the little black dot – now fully embedded into the Sun’s surface – jumped out at me. On the drive back to town, I saw people playing golf, walking down the street, driving in their cars, and I wanted to shout out the window: “STOP! You’re missing the last chance in your lifetime to see, with your own eyes, a planetary transit in our solar system!” But I didn’t. And they missed out. It’s funny, knowing astronomy doesn’t at all diminish the sheer joy and wonder of seeing objects millions of kilometers away carry on their cosmic dance, just as the laws of physics tell them to. I think it even enhances it. This is one of those days that I’m glad to be an astronomer.

Alice Olmstead
University of Maryland (Second year)My transit experience?  Clouds, clouds, clouds, glimpse of the Sun!!!, clouds, clouds…  Nonetheless, around 400 people made their way to the top of a parking garage to wait it out, many carting their own telescopes and cameras to add to the mix of equipment hauled over from the campus observatory.  Solar viewing glasses were pressed to people’s faces as they tried to catch the Sun coming out from behind the clouds – a few (not me, sadly) were able to catch the transit for several fleeting seconds.  The rest crowded into a tent to watch videos of the event online, or made jokes about being cryogenically frozen until the year 2117.  In spite of the uncooperative weather, everyone seemed to have a good time, and there was still a large crowd left even as the Sun set behind the last remaining patch of clouds, leaving an ironically clear sky in its wake.
Elizabeth Lovegrove, Nathan Goldbaum, Caroline Morley, Anna Rosen
University of California Santa Cruz (second and third year)The UCSC astronomy club set up a viewing event on a field near Porter College, next to a statue known as the ‘squiggle.’  Santa Cruz enjoyed clear skies and hundreds of people lined up all afternoon to take a look through the department’s telescopes. It was gorgeous weather for a transit in Santa Cruz: cloudless, deep blue skies and a crisp breeze to relieve the heat. The hill was dotted with department telescopes, homebrew pinhole cameras and amateur photography setups. Venus nicked the edge of the Sun right on schedule and I realized that on some level I hadn’t been expecting it to show up. It was one thing to be told that there was another planet in the solar system that was about to get in the way, and quite another to see it. When Venus appeared, my first thought was how perfectly circular it looked – like a neat round hole punched straight through the sun. Watching it transit, I felt the same awareness of space as I did during the annular eclipse a few weeks ago, watching the Moon cross where Venus was crossing now: a sudden, visceral sense that the silhouette I was watching represented a real place, a celestial body the size of the planet I was currently standing on, millions of miles away out there in space. The Earth is not alone! There are other planets out there around the Sun, and one of them got in the way! I thought about some of the exoplanet systems we’ve found, with as many as six planets spinning close in to their parent stars, and wondered what transits looked like from those worlds.I reveled in the shadow of Venus for a few hours, assisting the many students and other visitors who had come up to campus to watch. A few hours later, once the Sun had set and the grandeur of the event had faded, I discovered that, despite Venus’ best efforts, that cloudless blue sky had resulted in a nasty sunburn. Oh well. Totally worth it.  (Photo Credit: Mark Mozena & Scott Medling)  
Susanna Kohler
CU Boulder (4th year)I’m up in Anchorage, Alaska at the moment, having arrived a little early for the Summer AAS meeting. During the transit I joined folks at a public event put together by the University of Alaska Anchorage astronomers, complete with eclipse glasses, projection systems, solar scopes, and lots of curious and enthusiastic people. Since the sun here currently doesn’t set until nearly midnight, this was one of the few places in the US where one could witness the entire transit — we even met an astronomer from Mexico who traveled all the way up here just to watch it!
Kim Phifer
UCLA (first year)At UCLA, Astronomy Live!, an outreach organization run by graduate students, paired up with the Earth and Space Sciences department to provide solar telescopes, solar glasses and sunspot viewers to view the transit event from UCLA’s campus.  The event was very successful, with hundreds of people in attendance. The graduate students pictured are Tom Esposito (in green) and Breann Sitarski (in blue), who are both wearing Astronomy Live! t-shirts.

About Elisabeth Newton

Elisabeth was a Harvard graduate student and an astrobites and ComSciCon co-founder and is now a professor at Dartmouth College.

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