Transit (astronomy) of Mercury from Saturn and a transit of Venus from Saturn. No missions were planned to coincide with the transit of Earth visible from Mars on 11 May 1984 and the Viking missions had been terminated a year previously. Consequently, the next opportunity to observe such an alignment will be in 2084. On December 21, 2012, the "Cassini–Huygens" probe, in orbit around Saturn, observed the planet Venus transiting the Sun. On 3 June 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
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