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Mena (Mercurian Crater)
Mena is a crater in the Beethoven quadrangle on Mercury. Its name was adopted by the International Astronomical Union in 1976. Mena is named for the Spanish poet Juan de Mena, who lived from 1411 to 1456. Mena lies on the eastern rim of a larger unnamed crater, which is in turn within the much larger crater Vieira da Silva. Crater Type and Features Situated on the rim of an older, larger crater, Mena does not take on the typical bowl shape created by smaller impacts. Instead, Mena is classified as a complex crater with a peak located inside the bowl-shaped cavity. This peak is caused by a propagating shock wave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a med ... that rebounds and converges at the crater's center, causing the target material to be uplifted. Typically, the prese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MESSENGER
''MESSENGER'' was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for "Mercury Surface, Space Environment, Geochemistry, and Ranging", and a reference to the messenger god Mercury from Roman mythology. ''MESSENGER'' was launched aboard a Delta II rocket in August 2004. Its path involved a complex series of flybys – the spacecraft flew by Earth once, Venus twice, and Mercury itself three times, allowing it to decelerate relative to Mercury using minimal fuel. During its first flyby of Mercury in January 2008, ''MESSENGER'' became the second mission, after Mariner 10 in 1975, to reach Mercury. ''MESSENGER'' entered orbit around Mercury on March 18, 2011, becoming the first spacecraft to do so. It successfully completed its primary mission in 2012. Following two mission extensions, the spacecraft used the last of its maneuvering propellant to deo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
