What can tiny, highly charged particles arriving on Earth from outer space tell us about soil moisture content within wildfire burn scars in Colorado and Wyoming? Colorado State University civil engineers are testing the capabilities of a cosmic ray neutron rover to evaluate soil moisture across a variety of situations. “Because hydrogen in the environment is often contained in soil moisture, wet soils reduce the number of neutrons that occur in a certain energy range, while dry soils allow more of those neutrons to be detected. Measuring those differences allows us to estimate soil moisture across entire fields instead of at just a single point.” Stationary versions of these types of cosmic ray sensors have been used in agricultural research for more than a decade.