A report in Science shows evidence from the Messenger spacecraft that craters in constant shadow host water. A futher pair of Science papers show that much of the ice is beneath an insulating layer of dark material rich in organic and "volatile" molecules. The findings may help explain how these ingredients first arrived on Earth. Messenger was the first spacecraft to orbit Mercury, and since its arrival in March 2011 has been feeding back the best images of the planet that scientists have ever seen. The principal evidence for water ice comes from the craft's "neutron spectrometer", which can detect the subatomic particle neutrons as they stream from Mercury. "Neutrons are generated when cosmic rays hit a planet," Sean Solomon, Messenger principal investigator, explained to the Science podcast. read more http://www.bbc.co.uk/news/science-environment-20553879
