Clumps of Bacteria Could Spread Life Between Planets
For many years, astronomers have assumed microbes could float through the vastness of space like pollen in the wind, planting the seeds of life across the cosmos. New research suggests they might be. That would make life much more common in the universe than experts previously considered.
“The origin of life is the biggest mystery of human beings,” says researchers. They say that the team was able to show microbes would be able to survive the journey from Mars to Earth without shielding from the dangers of space if they clump together.
To do so, scientists took their experiments to space to see how terrestrial life handles being in such a harsh environment, where the vacuum, lack of oxygen, ultraviolet radiation and extreme temperatures would seem to preclude it. In the new study, researchers report how a specific type of bacteria on the International Space Station survived these harsh space elements for three whole years.
First, a NASA astronaut affixed densely packed balls of Deinococcal bacteria on exposure panels outside the giant space laboratory back in 2015. Deinococcus, which can be found high up in our atmosphere, is known for its unique ability to resist genetic damage from high concentrations of ultraviolet radiation and its tendency to form relatively large colonies.
After that, astronanuts looked at the pellets after one, two and three years. After their harsh three-year sojourn, the thinnest layers of bacteria were fried by ultraviolet radiation. But the dead layers of bacteria protected the DNA of the microbes underneath from getting too damaged to survive: researchers found that all samples bigger than 0.5 millimetres at least more or less survived the high-altitude hike. Experts suggest that a colony twice that thick – approximately the width of a coin – could live in space for up to eight years. That is more than enough time to travel from Earth to Mars, experts said.
This adds a level of feasibility to the panspermia theory, which proposes that life on Earth is the child of a distant parent. The idea is straightforward: life did not start on Earth, but, instead hitched a ride here from another location in our universe. The study is “very well conducted,” Researchers who were not involved in the study suggest. Some go on to say “Over the past four decades, all the predictions of cometary panspermia have been verified. This is very unlikely to happen for a theory that is wrong.”
Other experts in the field that were not part of the study have said that “a valuable addition to the growing body of evidence that extremophiles are very hardy and able to withstand the perils of outer space”. At least over short periods of time. Yet, other industry leading experts add that the new research also has serious implications on planetary protection and biological contamination – extremophiles similar to Deinococcus might have successfully hitchhiked on past and present spacecraft to Marts, inadvertently spoiling the pristine Martian environment. If we do one day find life on Mars, it may be challenging to tell if it was there to begin with or it drifted over from another planetary body.
Older studies have demonstrated that bacteria can survive in space when shielded by a rock, but other researchers findings might suggest bacteria can also survive by clumping together to create an “ark of interplanetary transfer” of life – a concept that excites many authors on the topic.
Ultimately, this is an exciting time for astrobiologist researchers everywhere. Deinococcus can pave the way for how we observe other extremophiles in environments that we previously thought it was impossible for bacteria to survive. Their “ark for interplanetary transfer” could massively influence our understanding of life growing in the universe as our space explorations get more far reaching.