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
NASA Earth Science NASA Earth Science NASA Earth Science, formerly called the NASA Earth Science Enterprise (ESE), formerly called Mission To Planet Earth (MTPE), is a NASA research program "to develop a scientific understanding of the Earth system and its response to natural and human-induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations". "To improve life here" and "To understand and protect our home planet," NASA supports research in the Earth Sciences and, as part of its Earth Observing System (EOS), launches and maintains Earth observing satellites to monitor the state of the climate, atmospheric