The blueness of the sky fades away as you get higher in the atmosphere. By the time you are in the lower troposphere, such as when flying in the upper elevations in a commercial jet plane—around 35,000 feet (about 10,600 meters)—the air is quite thin and begins to look dark. Above 150,000 feet (about 45,750 meters) the sky turns increasingly black as you enter the stratosphere.