Mergers have left four airline companies controlling more than 80 percent of the U.S. market. And they have been very slow to add new flights. That makes planes more crowded. U.S. airlines are filling more than 85 percent of their seats in some months â close to record levels, according to the government.
Pluto is thought to be made of mostly ice. It probably also has a small rocky core which might contain some metals. The ice on the surface of Pluto is made of frozen nitrogen, methane and carbon monoxide.The ice covering Pluto reflects a lot of sunlight making it appear brighter than it would if it had been covered with a darker rocky material. 1  Javascript must be enabled to use Cool Cosmos.t probably also has a small rocky core which might contain some metals. The ice on the surface of Pluto is made of frozen nitrogen, methane and carbon monoxide. The ice covering Pluto reflects a lot of sunlight making it appear brighter than it would if it had been covered with a darker rocky material.
Asteroids are made of rock and metal and broken away pieces of planets. They are grouped into three categories: Stony, Iron-Nickel, and a mixture of the two.Most asteroids that we know about fall into the first category, and are made of Silicates. A small percentage are Iron-Nickel.The rest form the third type. I believe that they are made of rocky bits left over from the formation of the inner planets. The run-of-the-mill asteroid is just one kilometer long.hey are grouped into three categories: Stony, Iron-Nickel, and a mixture of the two. Most asteroids that we know about fall into the first category, and are made of Silicates. A small percentage are Iron-Nickel.