The historic 2012 Transit of Venus commences today, June 5th, at 3:09 pm Pacific Daylight Time (22:09 UT). Astronaut Don Pettit had the foresight to pack a solar filter for his trip to ISS to photograph this event that won’t happen again for over a hundred years. He will be removing the “scratch panes” from the inside of the ISS cupola so he can take pictures directly through the optical quality glass windows.
Scientists on the ground will be looking at Venus’ atmosphere just as the transit begins and ends. The refraction of sunlight around the planet creates a bright arc, which varies with the temperature of the atmosphere.
Flickr site where Don Pettit’s pics will be posted.