United States Army Materiel Command. The U.S. Army Materiel Command (AMC) is the primary provider of materiel to the United States Army. The Command's mission includes the research & development of weapons systems as well as maintenance and parts distribution.
A comet is a small, icy object that orbits the sun and has a long tail of gas. Some comets can be seen from Earth every few years, while others pass by once in a person's lifetime. Comets are made of ice, dust, and tiny pieces of rock, but to people on Earth, they look like streaks or smudges across the night sky.
Although there can sometimes be a blurry line between categories the following definitions should help you understand the difference between comets and asteroids, why Halleyâs Comet is not a meteorite and more. Comet. A comet is a relatively small solar system body that orbits the Sun. When close enough to the Sun they display a visible coma (a fuzzy outline or atmosphere due to solar radiation) and sometimes a tail. Asteroid. Asteroids are small solar system bodies that orbit the Sun ...