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 Human Exploration Rover Challenge NASA Human Exploration Rover Challenge The NASA Human Exploration Rover Challenge, prior to 2014 referred to as the Great Moonbuggy Race, is an annual competition for high school and college students to design, build, and race human-powered, collapsible vehicles over simulated lunar/Martian terrain. NASA sponsors the competition, first held in 1994, and, since 1996, the U.S. Space & Rocket Center hosts. Students created vehicles dubbed "moonbuggies" to face challenges similar to those engineers at NASA's Marshall Space Flight Center addressed in preparation for Apollo 15. On that mission, on July 31, 1971, the first Lunar Roving Vehicle extended the range