Modern astronomy uses all regions of the electromagnetic spectrum.
The Earth's atmosphere absorbs most infrared light, as well as gamma rays, X-rays, and ultraviolet light. Flying at 41,000 feet, the KAO was above 85 percent of the Earth's atmosphere and more than 99 percent of the Earth's water vapor. In this clear, dry environment, astronomers aboard the KAO have studied radiant heat patterns from stars, planets, and other celestial sources - radiation normally absorbed by atmospheric water vapor before reaching the Earth's surface.