What is life? The question is as stunning as it relates to the philosophical aspect that the chemistry of life. We find that life evolves in time by taking a path defined by an infinite number of parameters, making it unpredictable and indefinable. There is however a biological definition of life: "A living organism is said when exchange of matter and energy with its environment maintaining its autonomy when it reproduces and evolves by natural selection. " All living organisms ensure their stability by reacting to changes in their environment.
Life has a faculty of adaptation and learning. Is it not rather this life? But we also see by observing galaxies, stars and planets, that matter is able to self-organize without being alive. However, a good definition of life should consider this concept, ie, the ability of the material to gradually climb the ladder of complexity. A study funded by NASA indicates that the heavy bombardment of asteroids that took place there nearly 4 billion years, not enough to completely sterilized the Earth. The study focused on an event known as the end of bombardment (Late Heavy Bombardment) or LHB.
The tenacity of life is it not proof that it is present throughout the universe, patiently waiting for favorable conditions to continue its path towards complexity? It's hard to believe that life exists only on Earth. Wherever there is liquid water, there is a possibility of life even under the icy crust of some planets and satellites of planets. Life is developing in places where even the sun's energy does not penetrate, we see into the depths of our planet. It recognizes life that when seen.