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The MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) probe, funded by NASA and managed by the Johns Hopkins University Applied Physics Laboratory, has produced the first images of the surface of Mercury taken from orbit around the planet.
The probe entered into stable orbit around Mercury on 17th March, after a 7.9 billion kilometre journey which began on 3rd August 2004 and has included a flyby of Earth, two of Venus and three of Mercury itself.
Above we show the first image obtained with the probe of a region near the south pole. The brilliant ray crater, "Debussy", dominates the image, that also includes regions never imaged before, even by Mariner 10 during its three passes of the planet between March 1974 and March 1975. For that mission only a single flyby was initially planned, but a clever application of celestial mechanics by Giuseppe (Bepi) Colombo resulted in a tripling of the number of passes. This is why the next major mission to Mercury, planned by ESA for 2014, will be called "BepiColombo".
After taking the above image, MESSENGER's Mercury Dual Imaging System continued to take images, obtaining 360 new images in just 6 hours. This marks the start of a phase of systematic study that will last for at least a year and will be focused on determining the composition and structure of the surface, its geological evolution, the nature of the magnetosphere and tenuous atmosphere, characterisation of the core (thought to be very large and possibly the cause of recent volcanic activity), and the search for ice in the polar regions.
In all, seven scientific instruments will be operating, all designed to work in the hostile environment around the planet closest to the Sun. MESSENGER's orbit is highly eccentric and in its 12 hour period, passes from just 200 km from Mercury's surface, to a distance of 15 thousand km.
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