Some solar radiation is absorbed by

Some solar radiation is absorbed by Earth materials,converted to heat, and then emitted from those materials as long wavelengths of invisible, thermal (heat) infrared radiation (TIR radiation, ). Earthmaterials warmed in other ways (e.g., fire, body heat produced by respiration, volcanic heat from Earth’s interior) also emit thermal (heat) infrared radiation (TIR). It is normally detected and measured by satellite instruments operating at night, when there is no sunlight to heat up surfaces. This allows geologists to see objects that emit heat on their own, even when they are not absorbing solar radiation and converting it to heat.