The half-ton orbiter known by its acronym MESSENGER was launched in August 2004 on a mission to study Mercury’s chemical composition, geology and magnetic field.
MESSENGER spiraled through the inner solar system for seven years before reaching its destination. Inserting MESSENGER into orbit proved to be a challenging task, due to the sun’s gravity, intense heat and effects of solar radiation pressure.
Among other scientific data, MESSENGER discovered the presence of frozen water in deep craters sitting in permanent shadow, as well as a mysterious dark material that could consist of organic compounds.
During its last month in orbit, MESSENGER sent back to NASA the best high-resolution images so far of Mercury’s desolate, moonlike surface.
voanews.com
30/4/15
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NASA spacecraft smashes into Mercury...
ReplyDeleteNASA's Messenger spacecraft has crashed into the planet Mercury after running out of fuel, in an incident expected by the US space agency.
On Thursday, Messenger - which stands for 'Mercury Surface, Space Environment, Geochemistry, and Ranging' - slipped out of orbit following a successful four-year tour of the rocky planet.
NASA said it was powerless to stop gravity from dragging the spacecraft towards the planet.
Its collision at a speed of more than 14,000kph added another small crater to Mercury's already-pitted surface.
Mercury is only slightly bigger than our moon and is the closest planet to the Sun, but until the $450m spacecraft arrived in Mercury's orbit in 2011, little was known about the planet.
Since then, the 485kg spacecraft has been using its seven scientific instruments to scan and feed back to Earth volumes of data.
"The material that Messenger has sent is enormous," says Francisco Diego, Senior Research Fellow at the Department of Physics and Astronomy at University College London.
"There are a lot of spectroscopic measurements, different gamma ray, x-ray spectrometers that characterised different depths of the soil of Mercury.".....aljazeera.com
30/4/15