Lunar and Planetary Institute

Apollo 17 Mission

Science Experiments - Infrared Radiometer

The Infrared Radiometer Experiment was performed on Apollo 17 to measure surface temperatures and cooling rates at night on the Moon by measuring the emission of infrared radiation from the lunar surface. During the lunar day, the surface heats up by absorbing solar radiation. At night, the surface radiates this stored heat back into space. The rate at which a given surface cools is related to the physical properties of the surface, particularly the material's density and thermal conductivity. This experiment measured temperatures between 85 and 400 Kelvin on different parts of the Moon. Results from this experiment also were used to determine the size of rock blocks in the ejecta blankets around impact craters and to determine how such rocks were distributed as a function of distance from the crater.