The last Venus Transit for 105 years is happening in a few minutes as I write this -- it goes from roughly 22:00 June 5 to 05:00 June 6 UTC (check your local listings).
Fraser Cain, Nicole Gugliucci, Pamela Gay, and I are hosting a live video chat of the transit with many amateur astronomers across the world! I am embedding it below:
[UPDATE (21:55 UTC): First view of Venus silhouetted against the Sun's corona are coming in!
This shot is in the far-ultraviolet, where the Sun's thin atmosphere, called the corona, glows. You can see the Sun on the right, and Venus -- which is dark in the UV -- is the dark circle on the left. Amazing. Credit: NASA/SDO]
For more info, you can read my lengthy post with a ton of info, or watch my interview with Cara Santa Maria on the Huffington Post. I also have a nifty video made up of images taken of the 1882 transit, too!