But Not Forgotten Mars, our closest sibling in the solar system, is the one who died in childhood. In my family, we have such a relative. I almost had an aunt. As such my mom grew up as a dearly loved only child, held all the more dear by the knowledge of the tragic loss that made her an only child. Our planet is the only place we know where the rush of life has transformed the usual carbon dioxide base of atmospheres to an oxygen-rich mixture suitable for genetic experiments such as ourselves.
Earth is both rare and fragile.
Svante August Arrhenius, won the Nobel Prize in chemistry in 1903 for his explanation of electrolysis. As unlikely as his theory seemed for many decades, the evidence is beginning to mount that Arrhenius' genius was greater than we possibly imagined. While the delivery mode is probably meteorites, in fact, life probably does travel from planet to planet and maybe even from star system to star system. Will Travel It is a paradox. Traveling the great Panspermia trade routes, ensconced on meteorites, it is predictable that everywhere it lands and there is an opening for it to establish a foothold, it will.