Is there life on Mars? The survival of terrestrial organisms outside the International Space Station during an 18-month experiment says it's possible.
On March 26, the German DLR Aerospace Center revealed certain types of Earth organisms lived for more than 500 days despite being exposed to extreme conditions.
This isn't the first time that organisms lived in space. In 2015, Jet Propulsion Laboratory studied five Enterobacter strains that infiltrated the ISS exercise platforms and toilets. Some types of bacteria also thrived during a 14-day shuttle flight, although they remained inside.
From 2014 to 2016, German researchers conducted Biology and Mars Experiment (BIOMEX) to determine the viability and survival of multiple organisms when exposed to different space environments.
They sent different kinds of organisms into space. These included bacteria, lichens, fungi, and algae. There were also unicellular organisms such the relatives of archaea, which lived on Earth for more than 3 billion years. The space sample was derived from the Arctic permafrost. Others were pigments and cell membranes.
Some of the samples ended up exposed to space's vacuum with extreme changes in temperature and intense UV radiation. Others were embedded in Mars-like soil and simulated atmosphere. The study went on for 18 months before the samples were sent back to Earth.
Based on their analysis, now published in Astrobiology, these terrestrial organisms survived for 533 days. Algae, in particular, lived for 16 months, making it a potential source of food on the red planet. The samples also remained detectable by the aerospace center's instruments.
"Some of the organisms and biomolecules showed tremendous resistance to radiation in outer space and actually returned to Earth as 'survivors' from space," said Jean-Pierre Paul de Vera, an astrobiologist who heads BIOMEX's scientific management.
The experiment didn't explain how these organisms survived or developed resistance to these conditions, but a previous study suggested they may be able to adapt to their environment when in space.
Is It Proof Of Life?
Mars is one of the closely studied planets for years. It's not only because it's one of the nearest to Earth but also because it's a potential human habitat.
Rover explorations helped scientists detect elements that may able to support life. These include nitrogen, phosphorus, sulfur, and even oxygen. It also holds water in ice form.
These studies, though, didn't prove any life-forms. The DLR experiment still doesn't guarantee that life does exist, but the results may suggest it's possible.
For now, the DLR researchers are developing instruments that can detect the metabolic products of these organisms. They are also set to present their findings in a scientific conference on March 27 to 29.