NASA's Solar Dynamics Observatory witnessed the entire transit. The proof? This amazing composite image
, comprising 15 different images of the transit as Venus moved from one side of the Sun to the other. The entire event took 7 hours... though you have add a bit more to include the planet blocking light from the Sun's corona, its superheated atmosphere.
This incredible event took a while to unfold, but it was seen by so many, and with an amazing array of tools. We'll learn more about Venus from this, and about planets orbiting other stars
, too. But I think the most important thing is that this literally opened the eyes of a lot of people and showed them the wonder and joy of the Universe around them. Credit: NASA/SDO; HMI