colored NASA image of Mars

Terraforming Mars could happen with these microbes

Contributed by
Jun 22, 2018

Missions to Mars are going to happen. Martian colonies are probably going to happen (whether or not we’ll live to see them is questionable). Could the transformation of a planet that had its atmosphere obliterated billions of years ago also happen?

Maybe. An international team of scientists recently discovered that cyanobacteria, which Earth was crawling with when it was still a massive ball of primordial ooze 3.5 billion years ago, can photosynthesize without much light. These life-forms that can only be seen under a microscope are kind of a big deal when you consider that they were involved in turning Earth’s toxic carbon dioxide atmosphere into breathable oxygen gas. That eventually created an ozone shield that kept solar radiation from scorching the planet—and they could possibly do the same thing for Mars.

“Photosynthesis could theoretically be harnessed with these types of organisms to create air for humans to breathe on Mars,” Elmars Krausz, who believes that terraforming Mars is more science than fiction and recently published a study in Science magazine with colleagues, told Cosmos Magazine. “Low-light adapted organisms, such as the cyanobacteria we’ve been studying, can grow under rocks and potentially survive the harsh conditions on the Red Planet.”

Cyanobacteria use photochemistry similar to the process which keeps the plants that evolved from them alive. Light is fuel for photosynthesizing organisms. They absorb red light, convert it into chemical energy, and reflect green light.


Credit: UC Berkeley

The experiment Krausz was a collaborator on, which was led by Dennis J. Nürnberg of the Department of Life Sciences at London’s Imperial College, tested how little red light these bacteria can live on before they are no longer able to photosynthesize. After exposing the bacteria to already low levels of red light, they kept lowering the wavelengths to find out the lowest that could possibly be absorbed.

The species cyanobacteria that proved it had what it takes to become Martian is Chroococcidiopsis thermalis (C. thermalis). The “red limit” was thought to be a wavelength of 700 nanometers until the team found out that C. thermalis can still photosynthesize at wavelengths of up to 750 nanometers, something that was previously missed because its long-wavelength chlorophylls in its DNA that had gone unknown. Investigating further into the genome of these science-defying microbes, the researchers discovered that the genes carrying those chlorophylls actually exist in other species of cyanobacteria.

So does this mean that microbes which spawned on Earth could succeed at infesting Mars? No one would know unless this was actually carried out, and then there are all the ethical implications of ecologically morphing one planet to be more like another without confirming there is (and never was) any life there.

For now, just the possibility of making that red desert remotely habitable is kind of mind-blowing.

(via Universe Today)