The Earth emits terrestrial radiation continuously throughout the day and night. Terrestrial radiation is the infrared radiation emitted by the Earth's surface and atmosphere, and it is a result of the Earth's temperature being higher than absolute zero. The amount of terrestrial radiation emitted depends on the temperature of the surface and the amount of moisture in the atmosphere. Warmer surfaces emit more terrestrial radiation than cooler surfaces, and dry atmospheres allow more terrestrial radiation to escape than humid atmospheres.