Discover the historical, observational, and scientific importance of Venus transits and see high-definition images from the 2012 transit in these NASA videos.Historically, a transit of Venus was used to try to measure the distance to Venus. The 2012 transit was the second of an 8-year pair that happens every 120 years. The Solar Dynamics Observatory captured videos and images of the 2012 transit of Venus in a range of wavelengths.