Transit of Mercury last four transits occurred on November 15, 1999; May 7, 2003; November 8, 2006; and May 9, 2016. The next will occur on November 11, 2019, and then on November 13, 2032. A typical transit lasts several hours. On June 3, 2014, the Mars rover "Curiosity" observed the planet Mercury transiting the Sun, marking the first time a planetary transit has been observed from a celestial body besides Earth. More generally, transits can also occur for Venus and were investigated in the context of searching for the hypothetical inner planet Vulcan. The most common observation to be made at a
International Year of Planet Earth International Year of Planet Earth The United Nations General Assembly declared 2008 as the International Year of Planet Earth to increase awareness of the importance of Earth sciences for the advancement of sustainable development. UNESCO was designated as the lead agency. The Year's activities spanned the three years 2006-2009. The Year aimed to raise $20 million from industry and governments, of which half was to be spent on co-funding research, and half on "outreach" activities. It was intended to be the biggest ever international effort to promote the Earth sciences. Apart from researchers, who were expected to benefit under the