Contrail Clutter over Georgia

Explanation: Artificial clouds made by humans may become so common they change the Earth's climate. The long thin cloud streaks that dominate the above satellite photograph of Georgia are contrails , cirrus clouds created by airplanes. The exhaust of an airplane engine can create a contrail by saturating the surrounding air with extra moisture. The wings of a plane can similarly create contrails by dropping the temperature and causing small ice-crystals to form. Contrails have become more than an oddity - they may be significantly increasing the cloudiness of Earth, reflecting sunlight back into space by day, and heat radiation back to Earth even at night . The effect on climate is a topic of much research . You can help NASA measure the actual abundance of contrails by participating in a contrail counting exercise that runs over the next two days.