At daybreak on June 8, a black dot appeared on the face of the sun – a phenomenon that more than 30 people had gathered to witness on the rooftop of U of T’s McLennan Physical Laboratories. For two hours, the group watched the Transit of Venus through U of T’s eight-inch refractor telescope. Then Earth’s sister planet reached the edge of the sun, elongated into a tear-drop shape as solar rays shone through the planet’s cloudy atmosphere, and disappeared.
You can call the viewing a tradition at the university – albeit a rare one. U of T faculty and students had also observed the transit in 1882. (The six-inch telescope that was used is on display at U of T’s Museum of Scientific Instruments Web site.) The transit only occurs approximately every 120 years (in pairs, eight years apart); the next one happens in 2012.
In 1882, scientists had embarked to all corners of the Earth, using the Transit of Venus to refine previous calculations of the size and scale of the solar system – measures now captured by radar. This time, U of T’s contingent simply enjoyed viewing the rare and beautiful event. Mubdi Rahman, an undergraduate astronomy student, had spent the night on the McLennan rooftop so that he wouldn’t miss its arrival. And 86-year-old astronomy buff David Calvin, who had been yearning to see it since he was a teenager – joined Rahman on the observatory deck. “I was hoping I’d still be alive to see it,” says Calvin. “And I was.”
“It was exciting to realize that really famous astronomers had wanted to see the transit in their lifetime, but couldn’t and here we were watching it,” says Preethi Nair, a PhD student in astrophysics. “It was also interesting to reflect on the advances from more than 100 years ago to now, which are huge and exciting.”
U of T’s astronomy buffs did discover one thing – the McLennan rooftop proved to be one of the very best places to watch the transit. While NASA’s broadcast from Athens was hampered by cloud cover, U of T observers “had a superb view…the clarity was striking,” says astronomy Professor Stefan Mochnacki. “It was a flawless, memorable morning.”