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.
Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several millions of years. Short-period comets originate in the Kuiper belt or its associated scattered disc, which lie beyond the orbit of Neptune.