Outer space is not in a perfect vacuum state, and there are interstellar clouds made of fine particles and gas in places between the stars. The region with the highest density in the interstellar cloud is called the interstellar molecular cloud. This area is a place where star formation is active. When a self-luminous star like the Sun ends its life, a large-scale explosive supernova occurs, and its shock wave hits an interstellar molecular cloud, which pushes it into a dense region., A new star is born from there.

Stars are born from the gas clouds of interstellar molecular clouds. Complex organic molecules, such as amino acids, that are materials for life have been found by radio observations of interstellar molecular clouds. Meteorites containing this organic matter fall on the earth and become the first material of life. It evolved in the sea and became a primitive cell, which is the starting point of all life, around 4.1 billion BC, and further evolved into a single cell.