Today we had a unique event! Mercury moved between us and the sun, showing up as a tiny disc against the sun. It wasn’t visible to the naked eye, but could be seen on photographs and with telescopes. On the East coast, the whole transit was visible, but here in Boulder, it had already started by sunrise. The whole transit lasted over 7 hours, starting at 7:12 am Eastern time. Go to NASA’s website for more information! Remember, never look directly at the sun, even with sunglasses. Use eclipse viewing glasses or a pinhole projector.
This event happens 13-14 times each century, either in May or November. The next transit of this century is November 11, 2019.
Here are some locally taken photos (a DSLR with a 300mm lens and eclipse glasses over the lens).
Mercury is the small circle at about 4:00 on the sun. The amorphous spot at about 10:30 is a sunspot.
The clouds came in near the end of the transit, making for a unique shot. Mercury is closer to the edge of the sun in this shot. Hard to see through the clouds, but still there.
To compare sizes, here’s a photo of the transit of Venus across the sun in June of 2012 (the next one will happen in December of 2117…start drinking from the Fountain of Youth now!). Venus is the large circle at about 1:30. The other dots in the picture are sunspots.