Law of conservation of minimal complexity
Complexity is the key attribute of life. Even the smallest living organisms like the microorganisms are extremely complex. Each is an individual cell distinct from the inanimate matter in which it exists. Actually the cell is an atom of life. Some believe that life can originate from inorganic matter, which has not yet been verified experimentally.
Simplify or remove the complexity of a living cell and it will cease to exist as such and become inanimate. There are two laws which characterize matter and life: Conservation of energy and the conservation of mass. Yet life is characterized by a third law, the conservation of minimal complexity. Imagine the following experiment. Take a suspension of bacteria, and heat it to 100 degrees centigrade. The first two conservation laws still hold. However the heat reduces (destroys) complexity and turns the bacteria to inanimate matter.
On the other hand you may cool the cells to near absolute zero. They will maintain their complexity, and show signs of life when warmed up to our room temperature. This experiment supports the assumption that cells may travel unharmed in outer space. They may have seeded our planet when the primordial soup cooled to a complexity preserving temperature. They probably continue seeding it even today, when comets enter our atmosphere.