According to Tomonori Totani, from the University of Tokyo, the number of stars in the universe is more than enough for RNA molecules to have formed by chance.
Tomonori Totani, an astronomer at the University of Tokyo, Japan, believes that the existence of life in other parts of our universe is almost a certainty. It’s all about probabilities.
Totani explains his reasoning in an article called “Emergence of life in an inflationary universe”, published on Nature. One of the essential molecules for life is ribonucleic acid (RNA), which is composed of chains of smaller molecules called nucleotides. According to the scientist, the smallest RNA molecule capable of self-replication (an essential characteristic of life) would be composed of between 40 and 100 nucleotides.
Given enough time and the right chemical conditions, nucleotides could combine spontaneously to form RNA and give rise to life. However, the number of stars in the observable universe (the part of the universe that we can “see”) would not be enough for that number of 40 to 100 nucleotides to be able to combine by chance.
“However, there is more to the universe than what we can observe,” said Totani. “In contemporary cosmology, it is agreed that the universe went through a period of rapid inflation, producing a vast region of expansion beyond the horizon that we can observe directly. The inclusion of this greater volume of stars in models of abiogenesis (life arising from non-living matter) greatly increases the chances of life occurring.”
The observable universe is estimated to have 10 sextillions (10 ^ 22) stars. However, in total it can contain up to 1 googol (10 ^ 100) of stars. “If this is the case, then more complex RNA structures, capable of sustaining life, are more than just likely. They are practically inevitable,” said the researcher.
“Combining my recent research on RNA chemistry with my long history in cosmology leads me to believe the universe may have gone from an abiotic (lifeless) state to a biotic state. It is an exciting idea, and I hope that research can expand it to discover the origins of life,” he says.