THE first spacecraft to orbit Mercury is almost out of gas. After discovering water ice, organic compounds and an iron core on the innermost planet, NASA鈥檚 Messenger orbiter will make one last thruster .
Engineers expect the 120-second engine burn to give the craft an 80-kilometre lift that will keep it aloft until March. But before then, as Messenger swoops low over the planet, it will heat up to 185 掳C and the metal solder holding some instruments together could melt.
In that time, the craft will get an unprecedented view of Mercury鈥檚 pockmarked surface, capturing data on its gravity field, crater contents and surface make-up.
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Because of the planet鈥檚 uneven gravity, the site of Messenger鈥檚 eventual crash landing is uncertain. But it will likely land on the far side, where it will be out of view until 2024, when the European Space Agency鈥檚 BepiColombo mission arrives.
To mark its impending demise, the is running a public contest to name five of Mercury鈥檚 craters.
This article appeared in print under the headline 鈥淢ercury melter鈥�
