The methods and technical means of mineral exploration are very diverse. One of them is the method of recording energy (brightness) contrasts of the earth's surface in the infrared region of the spectrum, which, in combination with others (photographic, magnetometric, etc.), can provide useful information. The article discusses the physical conditions of the existence of energy contrasts caused by the heterogeneity of the structure of the Earth's layers, as well as some questions about the possibility of registering and calculating them. ///