Comets are alive?

Danilo Anton

Behavior of comets is unpredictable.  They appear from nowhere, they dive into the inner solar system, they are made of ice and rocks and approaching the sun they sublimate their ices.They eject  strong plumes from their surfaces, together with the gases they expel dust particles which are blown by the solar wind forming a coma or a tail.  

They are very dark, their albedo is less than 5%. They are darker than coal. Almost black. Their ices are water,  carbon dioxide and several hydrocarbon and organic compounds and molecules. 

Suddenly they change their brightness without any apparent reason. 

Fred Hoyle, Wikramasinghe and others believe that inside the comets there are bacterial spores and that life came to Earth within these celestial bodies (this theory called "panspermia"). 
Once in a while a new comet hit our planet. Probably this is what happened in Tunguska, Siberia in 1908.  

It is possible that comets not only transport life, as bacteria or spores, they may even be alive themselves. In some way the coincide with the definition of an "organism" because in some way they are "born" and may finally die..  
They are born when they leave the deep freeze far away in the intestellar environment and start their activity during their solar approach. They die when they approach too much to the Sun or after a few thousand orbits next to the Earth and other interior planets. Some of them have elliptic orbits, and even, some have parabollic or hyperbolic orbits. Probably a few are extrasolar visitors . 
When they approach the Sun and they lose their ices they may become asteroids (which in some cases are "dead" comets. or they may disappear in the solar heat or disarticulate in smaller pieces..

The few interplanetary probes that visited comets have confirmed their unusual characteristics, particularly the impressive Rosetta mission which went to accompany comet 67¨/Churyurmov-Geramisenko in its orbit. Several organic molecules were identified during this mission and many doubts still arise about the internal dynamics of these small and mysterious spatial bodies.