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.
A comet is made up of material that gets evaporated easily by the Sun, so comets lose mass with each passage around the Sun. As much as one percent of their masses can be blown away. Comets may start out very icy, but this is not how they'll look for long, since the ice is the first thing to go.