Science, maths and computers.
This composite picture, put together by images from Japan’s Alos satellite shows intensely worked farmland in the Black Earth region of cropland, south of Moscow.
Three images, taken at different times of the year, and each coloured red, green and blue are superimposed upon one another. Strongly coloured parts of the picture reveal changes in the Earth’s surface over the year.
As well as detect these changes, subtle differences between different colour filters can also tell us what the crops are themselves.