NASA's Polar Radiant Energy in the Far-InfraRed Experiment (PREFIRE) mission will measure the amount of heat Earth emits into space from two of the coldest, most remote regions on the planet. Data from the mission will improve computer models researchers use to predict how Earth's ice, seas, and weather will change in a warming world. This artist's concept depicts one of two PREFIRE CubeSats in orbit around Earth. Earth absorbs a lot of the Sun's energy at the tropics, and weather and ocean currents transport that heat to the poles. Ice, snow, clouds, and other parts of the polar environment emit the heat into space, much of it in the form of far-infrared radiation. The difference between how much heat Earth absorbs at the tropics and then radiates out to space from the Arctic and Antarctic determines the planet's temperature and drives a dynamic system of climate and weather. But far-infrared emissions at the poles have never been systematically measured. This is where PREFIRE comes in. The mission will help researchers gain a clearer understanding of when and where Earth's poles emit far-infrared radiation, as well as how atmospheric water vapor and clouds influence the amount that escapes to space. PREFIRE is composed of two roughly shoebox-size CubeSats outfitted with specialized miniature heat sensors that will give researchers a more accurate picture of how much heat Earth emits into space. https://photojournal.jpl.nasa.gov/catalog/PIA26185