Bacteria discovery in Antarctica prompts rethink of humanity's search for alien life

Researchers have discovered a bacterium in Antarctica that can survive solely off chemicals in the air.Photo / Alan Gibson

Bacteria discovered in the icy continent of Antarctica is set to change the way humanity looks for alien life on other planets.

To date, our search for habitable worlds which could host alien life has been guided by what we know about life-conducive conditions on Earth. But in a new breakthrough, researchers have discovered a bacterium in Antarctica that can survive solely off chemicals in the air.

The microscopic organisms can survive just on hydrogen, carbon monoxide and carbon dioxide — opening up new possibilities about the existence of extraterrestrial life forms living in harsh conditions.

Antarctica is among the most extreme environments on our planet and it was previously thought the stresses of freezing temperatures, limited carbon, nitrogen and water availability along with strong UV radiation restricted life.

But new research reported in the journal Nature has shown the desert soils of Antarctica harbour surprisingly rich microbial communities.

"Here we provide evidence that atmospheric trace gases are the primary energy sources of two Antarctic surface soil communities," researchers wrote.

"We propose that atmospheric H2, CO2 and CO provide dependable sources of energy and carbon to support these communities, which suggests that atmospheric energy sources can provide an alternative basis for ecosystem function to solar or geological energy sources."

Essentially, the bacteria can survive with little sunlight, no geothermal energy and extremely limited nutrients.

The discovery was the result of DNA sequencing and analysis of soil samples collected from the icy continent.

"Although more extensive sampling is required to verify whether this process is widespread in terrestrial Antarctica and other oligotrophic habitats, our results provide new understanding of the minimal nutritional requirements for life and open the possibility that atmospheric gases support life on other planets."

Astronomers have historically sought out the potential presence of water when looking for planets which could support life but the bacteria findings show it's not the only indicator sufficient for life.

Exoplanets that were once not even considered to be candidates to hold life might be re-analysed to find habitable regions, said lead researcher Dr Belinda Ferrari.

"This new understanding about how life can still exist in physically extreme and nutrient-starved environments like Antarctica opens up the possibility of atmospheric gases supporting life on other planets," she said.