Over the last ten years, the rate of discovery of exoplanets has increased dramatically. Today, even Google's artificial intelligence is involved. With each new discovery announcement, the question that immediately arises is: when will we be able to explore these distant worlds? And the second question that immediately comes to mind is: is there life on these planets? These questions have given rise to several ambitious proposals, but the most daring or the craziest is the one put forward by a European scientist who, with his Genesis project, would like to sow life on distant planets.
Claudius Gros is a professor at Institute of Theoretical Physics from Goethe University in Frankfurt. In 2016, the latter published a post which described how robotic missions equipped with gene factories (or cryogenic pods) could be used to distribute microbial life to "transiently habitable exoplanets" - planets capable of supporting life but unlikely to give birth to life on their own. The project Genesis has since been refined. Now, in a new postProfessor Gros believes it is possible to use magnetic sails to equip spaceships carrying life to other planets.
Professor Claudius Gros (Photo: Bernd Hartung/die Welt)
Let's try to find out more about this curious idea...
We now know that an impressive number of exoplanets exist. They come in all sizes, temperatures and compositions. But there seems to be a consensus among most scientists that "simple" life - that of elementary microorganisms - must be very common in the universe. But "complex" life - that of evolved organisms - must be much rarer.
Under optimal conditions, simple life can develop very quickly. Complex life, on the other hand, takes much longer to evolve. Claudius Gros reminds us in an interview to Universe Today that " on Earth, it took a long time for complex life to arrive. The Cambrian explosion didn't happen until about 500 million years ago, about 4 billion years after the formation of the Earth. ». His idea is to give exoplanets the opportunity to move rapidly forward in evolution. A kind of acceleration of time. « We can give them the chance to have their own Cambrian explosions." " he says. " But this possibility is not applicable to all exoplanets. It is necessary to select those which are "habitable ".
The main candidates are habitable "oxygen planets" around dwarves. Claude Gros states: " It is very likely that the oxygen-rich primary atmosphere of these planets will have prevented abiogenesis, i.e. the formation of life. Our galaxy could potentially harbour billions of oxygen-rich, habitable but inert planets. "
So let's imagine planets that can support life. What kind of organisms would be sent? Well, first of all, " photo-synthetic bacteria, such as cyanobacteria and eukaryotes. (the cell type that makes up all complex life, i.e. animals and plants)," says the researcher. « Heterotrophs, those organisms that feed on other organisms that can only exist after the existence of autotrophs, would come in a second stage. ".
Claudius Gros seems to have a clear idea of the profile of candidates for the future colonization of space.
But how do you send them, especially at distances that are calculated in light years?
For Claudius Gros the question of shipping these organisms depends on the level of technology reached at the time the problem arises. Several solutions would be possible, according to him. One could miniaturize a "gene factory" or send frozen germs into space. Another option would be to send synthetic life. Synthetic biology is currently making enormous progress and is already capable of reprogramming the genetic code. We can then imagine creating new life forms based on a different code from the one we know. Professor Gros acknowledges that this method is highly dangerous if done on Earth, but on a distant planet it could, in the eyes of the scientist, prove extremely beneficial.
The question that arises is not only the relevance but also the usefulness of such an approach. What benefit can humanity derive from this seeding of space? All the more so since, distances being so remote that, in the present state of our technologies, we would not be able to see the results of these initiatives for several thousands or even millions of years. Dr. Gros acknowledges that it is not very rational to talk about "benefit" in the short or medium term. But on a longer scale, why not.
Can we one day bring life to distant worlds?
As you might expect, there are many criticisms of Dr. Gros' Genesis project. They can be grouped into three categories.
The first is religious. What allows man to play the role of God? Claudius Gros answers by saying that his Genesis project is not about creating life, but about giving life the opportunity to develop further. Certainly not on Earth, but elsewhere in the cosmos.
The second criticism relates to planetary protection. This concept obliges us not to "contaminate" space with terrestrial organic forms. The space agencies are very attached to it during space missions. Claudius Gros replies by reminding us that his project, on the one hand, does not target complex life forms and, on the other hand, only targets so-called inert exoplanets, i.e. those where no life forms are detected.
The third argument concerns the lack of benefit to humanity. If we think that ethics could be defined by "what is good for humankind", we can say that this project is not ethical. Dr. Gros is not far from thinking so, in that sense of the term, but the passion for research and discovery seems, as far as he is concerned, to prevail.