The last transit of Venus took place recently on 5 and 6 June 2012, and it was the last Venus transit of the 21st century. Venus transits are very rare events. The next one will be December 10–11, 2117. So it is much likely that this on was the very last Venus transit I had a chance to see in my lifetime.
M. Atzmueller, S. Doerfel, A. Hotho, F. Mitzlaff, and G. Stumme. Modeling and Mining Ubiquitous Social Media - International Workshops MSM 2011, Boston, MA, USA, October 9, 2011, and MUSE 2011, Athens, Greece, September 5, 2011, Revised Selected Papers, volume 7472 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, Heidelberg, Germany, (2012)
B. Macek, C. Scholz, M. Atzmueller, and G. Stumme. 23rd ACM Conference on Hypertext and Social Media, HT '12, page 245-254. Milwaukee, WI, USA, June 25-28, 2012, ACM, (2012)Best Paper.
C. Scholz, M. Atzmueller, and G. Stumme. Proc. Fourth ASE/IEEE International Conference on Social Computing (SocialCom), Boston, MA, USA, IEEE Computer Society, (2012)