The first colonists on Mars may not be humans but tiny microbes that will kickstart the biological processes needed to support life.
The surface of Mars is currently barren, frozen and uninhabitable, but it doesnt have to be that way, according to a new study.
By "infecting" Mars with the bacteria, viruses, and fungi that support lifes processes here on Earth, scientists claim the Red Planet could eventually become habitable.
"Life as we know it cannot exist without beneficial microorganisms," said Jose Lopez, a professor at Nova Southeastern Universitys Halmos College of Natural Sciences and Oceanography.
"To survive on a barren (and as far as all voyages to date tell us) sterile planets, we will have to take beneficial microbes with us."
Space entrepreneurs such as Elon Musk and Jeff Bezos, as well as space agencies such as NASA, are already exploring the idea that we may need a "Planet B", as Earths natural resources become depleted and the human population exponentially increases.
Lopez and colleagues are now urging these players to invest in microbial research, to determine which microbes would be the most beneficial to send into space.
The paper suggests the best candidates might be extremophiles - organisms that thrive in the most extreme environments, such as tardigrades.
It claims that these microbes should be sent to Mars and other potentially habitable planets before humans, to begin the terraformation process.
"Life on earth started with relatively simple microorganisms which have the capacity to adapt and evolve to extreme conditions, which defined earths habitats in the ancient past," Lopez said.
"Cyanobacteria for example provided most of the oxygen we now breath more than two billion years ago."
In the long run, these efforts will save humanity money, can be life-sustaining and boost microbiological understanding, according to Lopez.
However, the proposal goes directly against the strict no-contamination guidelines that NASA and all space programmes have closely adhered to for decades.
Before embarking on a journey into space, all equipment is carefully sterilised and protected from germs and contaminants - just like in a hospital.
This is to prevent contamination of the untouched environments scientists are trying to investigate.
Lopez and colleagues argue it is inevitable that microbes will eventually be introduced to other planets - either accidentally or deliberately.
"We hypothesise the near impossibility of exploring new planets without carrying and/or delivering any microbial travellers," the paper states.
However, he acknowledges that this is not something that should be rushed.
"This will take time to prepare, discern and we are not advocating a rush to inoculate, but only after rigorous, systematic research on Earth," Lopez said.