What do The Andromeda Strain, Project Hail Mary, and extremophiles have in common? If you answered survival, you’d be partly correct. The results of an experiment on the International Space Station may be the key to surviving space radiation. Or is it proof that life can (has) spread through the universe?
Radiation in Space
We’ve all heard about it. Scientists have studied its effects on meteors and rockets and astronauts for years.
Space radiation is made up of three kinds of radiation: particles trapped in the Earth’s magnetic field; particles shot into space during solar flares (solar particle events); and galactic cosmic rays, which are high-energy protons and heavy ions from outside our solar system.
NASA
This is of particular concern when astronauts travel beyond low Earth orbit. Space radiation may place astronauts at significant risk for radiation sickness, and increased lifetime risk for cancer, central nervous system effects, and degenerative diseases. On a trip to and from Mars, astronauts will endure at least fourteen months of radiation exposure. Depending on their mission, it may be many months more. Space radiation is of increasing concern here on Earth as the protective layers of atmosphere above us grow thinner.
Starting the Experiment
In 2015, the robotic arm on the International Space Station mounted three boxes of balls of extremophiles on a handrail. They stayed there, 250 miles above Earth, soaking up all forms of space radiation. They also endured the vacuum of space and extreme temperature swings as the station rotated in and out of the sunlight.
What are extremophiles?
Extremophiles are organisms that live in extreme conditions, such as in a hot spring or an ice cap or an under sea volcanic vent.
In the late 1960s, a microbiologist named Tom Brock discovered and identified the first extremophile in the Great Fountain region of Yellowstone. Since Brock and his colleague identified the microorganism, more and more extremophiles have been discovered. Microbiologists and astrobiologists have studied the organisms ever since. They estimate extremophiles have lived on Earth for more than forty million years.
The Experiment
Three panels of the bacteria, Deinococcus radiodurans, arrived on the space station via a SpaceX rocket.
According to smithsonianmag.com each panel contained two small aluminum plates dotted with twenty shallow wells for different-sized masses of bacteria. The largest of the masses, or balls, of bacteria was thinner than a millimeter.
They positioned one panel pointed down toward the International Space Station; the other pointed out toward the cosmos. Astronauts collected one panel after it was in place for a year and sent it back to Earth for study. They colleced the second panel and sent back after two years’ exposure. They collected the third panel at the end of the third year and sent it to Earth.
The results showed the outer layers of the balls, or masses, of bacteria died and while those inside survived.
How’d The Cells Survive?
The articles I read implied the cells balled up into layers as a protective mechanism, an instinct, so to speak. In addition, this particular bacteria carries up to ten copies of their DNA (humans carry two). Having more DNA means they can churn out more of the proteins that repair cells damaged by radiation.
What is the Meaning of This?
This finding suggests that life could transport between planets on a meteor or other space debris. Some speculate that it hints at the origin of life on Earth. Others speculate it could mean life transferred from Mars to Earth or other planets.
Astrobiologists and microbiologist identified the parts of the bacteria’s genes that create the radiation-repairing proteins. Other scientists have identified various parts of human DNA that change due to living in space (in part due to astronaut Scott Kelly’s year in space).
The scientists don’t have all the answers yet. But they may have found the key to surviving space radiation making long-term space flights safer. Will it mean they trigger human genes to produce those radiation-damage repairing proteins? Or will they manipulate human genes to be more like the extremophiles and create a being suited for space travel similar to what happens in Man Plus by Frederik Pohl?
Imagine you’re an astronaut and going to Mars is all you ever wanted to do. Would you allow scientists to turn you into an extremophile?
Image Credits
Top image NASA/Roscosmos, Public domain, via Wikimedia Commons
Last Image: by James Wheeler from Pixabay