I am only a humble messenger of Máximo Sandín’s work.
«Star Travelers» intends to generate reflection and many doubts. As Carl Sagan said, «The first great virtue of man was the doubt. »
All the knowledge, reasoning and ideas of any scientist that generates a discussion make science.
I assure you all the conclusions by Professor Sandín are based on papers by other scientists, which you will find on his personal website that’s mentioned in the book.

Hydrogen is the most abundant element on the known universe, and iron is the most abundant metal. Does anyone know for sure how they were formed? We will probably never know, but the truth is they are inherent in the universe just like other gases and minerals are. It seems proven that rests of organic matter (life) have been found in icy meteorites. Thus, can’t life be inherent in the universe just like gases or minerals are, and perhaps it fructifies where conditions are most favorable? 

According to biologist Lynn Margulis, eukaryotic cells seem to have originated from endosymbiosis between bacteria. But certain elements in eukaryotic cells could only be provided by viruses and not by bacteria. So I wonder whether bacteria and viruses are not fundamental in the life process of any living thing. 

Star Travelers is a book for young audiences and it invites you to learn more about its content in Professor Sandín’s website.    

As a way to come to an end, as Carl Woese said: «A society that permits Biology to become an engineering discipline, that allows science to slip into the role of changing the living world without trying to understand it, is dangerous to itself. »