Science Daily April 17th (www.sciencedaily.com/releases/2010/04/100416185151.htm ) … as the solar wind flows over natural obstructions on the moon it may charge polar lunar craters to 100s of volts according to new NASA calculations. Polar lunar craters are an object of interest as a possible source of water for astronauts and have therefore attracted interest. The moon’s orientation towards the sun keeps polar craters in permanent shade – allowing temperatures to plunge to -400 degrees Fahrenheit. Knowledge of the environment of the moon has been changing in recent years and scientists are worried by what the solar wind can do – composed of electrically charged electrons and ions. The solar wind flows horizontally over the lunar surface at the poles and computer simulations have been used to estimate what might happen.