The Transit of Venus

A stellar journey in amateur astronomy

By Dylan Hackett, News Editor

The Transit of Venus—a rare orbital occurrence in which we can see Venus pass across the sun—is a lifetime highlight for many amateur astronomers. To witness an event with the historical impact, astrophysical significance, and celestial beauty of the transit is for many astronomers, worldwide, an event as significant as the birthday of a centenarian. The viewing of the transit on June 5, however, involved a focus on revisiting of the past.

Douglas College astronomy instructor Jennifer Kirkey arranged a viewing of the transit at the college. Due to the foul overcast plaguing the city in this month (donned by many as “Juneuary”), the small group of us who had planned to look at the Transit of Venus from the balcony outside of the New Westminster Aboriginal Gathering Place instead conceded to the Vancouver weather and glued our eyes to a web broadcast from NASA’s facilities at the top of Mauna Kea, Hawaii at 4,205m above sea level.

By 3:12 p.m., I could see Venus, just a small black dot, making her passage across the infrared image of the sun at the 8 o’clock mark.

Second contact came at about 3:26 p.m., where we could see Venus not just as a mark in the corner of our sun, but as a dot on an orbital mission. The room was rapt at the sight of the transiting planet and murmurs of wonder could be heard behind me from the mouths of the unseemly keen. There was no collective “ahhh” of awe, but this wasn’t a stellar sight with the instant shimmering gratification of say, a meteor shower. The beauty was in the deeper though—like in the imagining of the many before us who travelled thousands of kilometres across the planet in a race to make the first calculations of the distance between us and the sun.

The Royal Astronomical Society of Canada Vancouver Centre is a popular congregation of both the amateur astronomers of the area and the professional caste who gravitate toward observing in their leisure time as well as at work. Having a chance to chat with some inspirational amateur astronomers who I co-volunteered with at the SFU Open House as Rocket Launch Managers at the Solar System Spurt station (a child-oriented astronomy adventure which scaled universe size along a stone pathway) helped me to learn operations of the RASC, stargazing, as well as the significance of the transit.

“It’s a chance of a lifetime. It’s quite an unusual event—it’s only been witnessed six times in history, so this will be the seventh opportunity for mankind, humans to witness the transit,” mused Alan Jones, vice-president and secretary on the RASC council.

Members heralded the RASC ‘s telescope loaning system for members. The group provides access to quality telescopes in-between the monthly meetings for any member who signs up. Leigh Cummings, Chair of the Antony Overton Memorial in Maple Ridge explained that diving straight into telescopic observing is probably not the best idea for those first lending their eye to observing the night sky.

“It’s not like jumping onto a pair of roller skates and learning. It’s an investment. I usually recommend to people that they get binoculars first because if you find that astronomy is not for you, you can use them for bird watching or sports events and things like that,” Cummings explained. “Going to events like the Star Party up at SFU you get the chance to learn from other astronomers. Certainly a lot of my learning has been done at these events where you meet other people.”

For many of those involved in amateur astronomy, it seems that the social aspect of observing with likeminded people of all, ages, professions, and backgrounds keeps them bonded to their telescopes as well as socially engaged in collective learning. It’s much like taking your favourite college course with some of your best friends.

“Metro Vancouver Parks does a thing every summer with the RASC and we have it out at Aldergrove Lake Park,” Howard Trottier, SFU physics instructor and RASC member, explained how the group enjoys annual August meteor showers. “RASC will be there with telescopes all night and we camp there. If you get there before 11 p.m. then you’re allowed to stay all night. It’s a party atmosphere and it’s one of the significant RASC events of the summertime.”

Seeing the transit through the eyes of a multimillion-dollar infrared telescope transmitted onto a classroom projection screen was not what I had planned, but the massive scale of the image gave me a real scale of the size of my planet of dwelling and my size accordingly. I was watching Venus, a tiny black dot, travelling across the sun—a superheated ball of hydrogen with the diameter of 109 earths. It was not since seeing the Milky Way above me on a 3 a.m. trip out to the outhouse at five years of age while camping in the Okanagan that I had been stunned by such a dwarfing epiphany.

The transit of venus as captured by the Solar Dynamics Observatory satellite currently orbiting Earth (Photo courtesy of Nasa)
The transit of Venus captured by the Solar Dynamics Observatory satellite currently orbiting Earth (Photo courtesy of NASA).

Stellar facts

The Transit of Venus has had important historical significance for science and discovery helping mankind learn more about the solar system and the wonders of Earth’s sister planet. Here are some facts relating to the planet and its transit across the sun!

  • Johannes Kepler, a man whose namesake has been lent to a lunar crater, a New Zealand hiking trail, a right angle formed by three squares, and a Seattle college, first predicted a Transit of Venus in his 1627 calculations and died before that predicted transit took place in 1631.
  • The next transits in 1761 and 1769 provoked a wave of astronomical discovery and provided the first opportunity for accurate estimates for the distance between Earth and the sun to be calculated. Of those racing to make calculations were Charles Mason and Jeremiah Dixon—men whose names were used to mark the notable boundary (Mason-Dixon Line) in the United States that divides the borders separating the north states and the southern states which had legalized slavery.
  • Famous explorer James Cooke, who first explored much of Vancouver Island and the Pacific coastline, observed the Transit of Venus from Tahiti in 1769.
  • During the 1761 transit Russian astronomer Mikhail Lomonosov discovered that Venus had an atmosphere by noticing the ring of light around the planet at the beginning of the transit. What Lomonosov didn’t know is that the atmosphere was composed of poisonous carbon dioxide and nitrogen.
  • Like Earth’s clouds, the clouds on Venus are capable of striking lightning. The clouds on Venus however, are largely composed of sulphur dioxide: a poisonous chemical used to keep early refrigerators a cool temperature in the early 1900s. These fridges were prone to leakage.
  • The transit of 1882 was the first to be photographed by David Peck Todd. The glass negatives from his photographs were rediscovered in 2002 and sequenced to make the first ever movie of the transit!
  • Composer John Phillip Sousa composed a military march in honour of the 1882 Transit of Venus. To the modern ear the song sounds more suiting to the stereo system of an ice cream truck than from the ranks of a brass military band.
  • It is possible for the Transit of Venus to occur at the same time as a solar eclipse. The last time this happened was while Stone Age humans were spreading across the Americas in 15,607 BCE. The next time this is poised to happen will be on April 5, 15232. Hopefully we will have colonized the moon by then and will perhaps observe from both the Earth and the moon!