Creatinine is a toxin produced during the metabolism of meat in our body. Therefore, people with lots of muscles or who eat lots of meat always have a relatively high creatinine level, but it usually fluctuates in the normal range: 0.5-1.3mg/dL.
comet definition An object that enters the inner solar system, typically in a very elongated orbit around the sun. Material is boiled off from the comet by the heat of the sun, so that a characteristic tail is formed.
Here is what scientists have found out. Comets are part of the solar system. They orbit the Sun, just as planets do, except a comet usually has a very elongated orbit. Part of its orbit is very, very far from the Sun and part is quite close to the Sun. A comet's nucleus is like a dirty snowball made of ice. As the comet gets closer to the Sun, some of the ice starts to melt and boil off, along with particles of dust. These particles and gases make a cloud around the nucleus, called a coma. The coma is lit by the Sun.