These pages address fundamental questions about soil and soil moisture, and are intended to provide a background to the whole subject of soil moisture. There are whole books dedicated to addressing these subjects so what has been included here is very much an introduction that we hope provides sufficent understanding of why the COSMOS-UK project is important and worthwhile.

The first parts look at soil, soil moisture, and the reasons why soil mositure data are interesting and valuable. The last part includes a basic description of how the cosmic-ray soil moisture sensor works and how this compares to other measurement technologies. A more detailed description of the science behind the cosmic-ray sensor can be found in the publications under Science and Resources.

What is soil?
What is soil moisture?
Why measure soil moisture?  
How is soil moisture measured?