A rare phenomenon occurred on 2012 June 5-6: the planet Venus was in transit in front of the Sun. The previous transit was in June 2004 and the one before was in 1882 (one of the only existing photography of the solar disk and Venus during the 1882 transit). The observation of the 1882 Venus transit was the most well-known instance to measure the distance between Earth and Sun, that distance being used as the base unit for distances between all heavenly bodies.
The June 2012 transit of Venus was the last one in our lifetime, the next such alignment occurring in 2117. I was planning on observing the Venus transit from the Big Island in Hawaii, at the 4,200-meter high CFHT on top of the Mauna Kea. However high winds and the many observers made me relocate to the 3,400-meter high Mauna Loa Solar Observatory where the winds were not as strong. Unfortunately the seeing was far from perfect, particularly during the last two hours of the transit. Worth to mention is that it was a real pleasure to see that during two controls TSA agents mishandled my observation equipment resulting in damaged equipment as they failed to repack correctly according to the provided instructions.
On the 2012 Transit of Venus visibility map you can see that since we are at the end of spring there is an area around the North Pole where the Sun never sets, the whole transit being visible with the Sun low on the horizon.
Inversely, around the South Pole, there is an area where the Sun never rises, the transit being invisible. You can also notice two zones, one to the south where the Sun will rise and then set and one to the north where the Sun will set and then rise during the transit.
Unlike the 2004 transit, which was not visible from Pointe Vénus in Tahiti, the 2012 June 5 one did allow a repeat of the 1769 observations by James Cook.
To find out if you could have observed Venus during the June transit, use this Venus transit calculator.
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