Cyanobacteria: The first seed of space colonization

Making way for a multi-planetary species

Here’s a chart that shows the oxygen levels in the Earth’s atmosphere over the past 4 billion years.

The x-axis shows time in billions of years and the y-axis shows the amount of atmospheric oxygen. The green and red lines give the estimated range. Source: Wikipedia

Notice something weird? There is practically no oxygen in the Earth’s atmosphere until about 2.5 billions years ago. Then the oxygen levels in the atmosphere increased dramatically after this period. What led to this Great Oxygenation Event?

Cyanobacteria.

Cyanobacteria and their unique history

Cyanobacteria are unicellular bacteria that derive their energy from photosynthesis. They are thought to be the first species to develop the ability to photosynthesize. Generating oxygen as a byproduct of photosynthesis was a game changer that eventually led to the proliferation of multicellular organisms and therefore to animal life on Earth. What’s more, cyanobacteria are the only species to invent photosynthesis in the history of our planet — all plants and algae have derived this ability from them.

A large bloom of cyanobacteria in Lake Atitlán, as seen from space. The lake is in Guatemala, Central America. Source: NASA

Having survived for billions of years and having a wide genetic diversity, cyanobacteria are found almost everywhere, be it on land or in water. They can bloom in ocean water or survive in highly dry deserts. Some species of cyanobacteria even thrive in the Antarctic rocks. Cyanobacteria are extremophiles, meaning they are capable of surviving in extreme environments. Cyanobacteria even survived outside the International Space Station (ISS) for 16 months.

Microorganisms mounted on trays outside the ISS, exposed to the harsh space environment for 16 months. Source: Farunhofer.de

They were mounted on trays outside the ISS, where they were subjected to extreme radiation levels and temperature variations. Not only did they survive for 16 months, they also adapted well to the coldness of vacuum.

Cyanobacteria were the architects of the Earth’s atmosphere, now they may be the architects of a space civilization.

The unique mechanisms that cyanobacteria have combined with their extremophile nature have sparked ideas for interesting applications in space exploration.

How cyanobacteria can be used for space settlement

The useful applications of cyanobacteria in space exploration cover a wide range:

  1. Energy source: In the process of photosynthesis, cyanobacteria expel free high energy electrons into the environment, thereby generating electricity from sunlight. Explorations into ways to utilize this electricity by engineering internal photosynthetic pathways of the cyanobacteria are currently on. This could allow for a clean, reliable and efficient energy source for small applications in space missions, where other sources aren’t viable.
  2. Oxygen source: The idea of terraforming Mars using cyanobacteria to generate oxygen in the atmosphere has been thrown out. Carbon dioxide comprises of 96% of the Mars atmosphere. We humans need oxygen to survive and cyanobacteria can convert the ample supply of carbon dioxide into something we can breathe.
Composition of the atmosphere of Venus and Mars compared to Earth. Mars has 96% carbon dioxide and very little oxygen. Source: Wikipedia

3. Agriculture: The species of cyanobacteria called Microcoleus vaginatusare retain water in soil and prevent erosion. This potentially makes them very handy for farming on custom-engineered alien soils where water wouldn’t be readily available.

Enter Lab2Moon

All of the world-changing applications (literally!) of cyanobacteria can be realized only if they can reliably work in the hostile environments of outer space. While cyanobacteria have been tested extensively in harsh conditions on Earth across multiple experimental setups, space environments are far more hostile. The next step is thus to see how they react to extreme space environments. This is precisely the aim of 3 Lab2Moon experiments on board the TeamIndus Moon lander.

#1: Space4Life — Developing a radiation shield using cyanobacteria

The electronics of a spacecraft and any humans aboard need to be protected from the damaging radiation and cosmic rays of outer space. Lead has traditionally been the standard material to achieve this. However, the minds behind @Space4Life want to harness the extreme radiation-surviving properties of cyanobacteria instead. Here is how it compares to lead and aluminum.

Comparison of radiation shields made of lead, aluminium and cyanobacteria. Source: YouTube

Lead shields are effective but heavy and aluminium shields are light but ineffective. A cyanobacterial radiation shield can be both lightweight and effective, while being cheaper than lead. This will be put to the test after the TeamIndus spacecraft lands on the lunar surface next year. If successful, it has amazing implications for the future of space exploration.

#2: Biocon Team ZΩI: Photosynthesis on the Moon by cyanobacteria

Having already survived on the outside of the International Space Station for 16 months, testing whether or not cyanobacteria can photosynthesize on the radiation-showered lunar surface is the next step. Biocon @Team ZΩI wants to observe how cyanobacteria photosynthesize in such an extreme environment, given only the fundamental resources. The potential benefits of this experiment are huge. If cyanobacteria can photosynthesize effectively under harsh conditions, they can be used to terraform planets as discussed above.

Cyanobacteria can pay a major role in the terraforming of Mars or other planets. Source: Wikipedia

#3: Killa LAB: Testing cyanobacterial growth under radiation

UV radiation and cosmic rays can damage the DNA of life forms. Exposure to such radiation is plentiful on the lunar surface on the dayside.

UV radiation damages DNA by tangling and distorting its ladder-like structure, causing a range of health problems such as skin cancer and diseases affecting the immune system. Source: NASA

The idea of @Killa LAB is to image how cyanobacteria change their form in response to the radiation. It will help us understand how the cyanobacteria adapt and grow in such an environment and goes a long way in ensuring that cyanobacteria can be used in space exploration.

Conclusion

Given their genetic diversity, global presence and fundamental importance, cyanobacteria are arguably one of the most — if not the most — successful species on Earth. If they live up to even some of this potential, we may be able to make the leap to an interplanetary species. The baby steps start right now.

As one of the Lab2Moon judges, Dr. Priya Natarajan, put it:

“Now the major problem of space is no more physical, it’s biological.”


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