The moon is about to get a new crater, courtesy of the lunar orbiter SMART-1, which is due to crash-land on Sunday.
Controllers at the European Space Agency used the spacecraft鈥檚 last fuel to aim it at the near side of the moon. The crash should happen at about 0530 GMT on a plain called the Lake of Excellence, but it might occur one orbit (about 5 hours) earlier if the low-flying spacecraft happens to meet an unmapped mountainside.
SMART-1 will hit the ground at about 7000 kilometres per hour. 鈥淚t鈥檚 likely to ricochet off the surface,鈥� said chief mission scientist Bernard Foing. 杏吧原创s expect the probe to gouge out a crater 3 to 10 metres wide.
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The impact site will be in darkness, so the glare of the sunlit surface will not overwhelm observations. Ground-based telescopes should see a plume of dust lit up by earthshine, the light reflected from Earth. Their observations could reveal the composition of lunar soil at the crash site.
If some of the debris flies up to a height of 20 kilometres, it will catch the sunlight, and amateur astronomers with small telescopes or even binoculars might see a bright dust cloud.
SMART-1 has orbited the moon more than 2000 times, mapping lunar minerals, which will help scientists piece together the history of the moon. But the orbiter鈥檚 main purpose was to test new technologies, including an innovative engine that nudged the spacecraft through space by expelling xenon ions.
