DNA molecules planted on a sub-orbital test rocket’s exterior are capable of surviving a trip to outer space and back, according to The Los Angeles Times. This discovery, published in the online journal PLOS One, suggests that genetic material may have the potential to stow away on rockets or within meteors.
Scientists from the University of Zurich plastered the bioengineered plasmids on the rocket’s exterior and onto some screw heads. The genetic material was then subjected to 6.3 G’s of thrust, six minutes of microgravity, and temperatures exceeding 1,000 degrees Celsius.
The DNA was engineered into ring-like strings that would grant special qualities to transfected cells, according to The Los Angeles Times. For example, bacteria could become resistant to certain antibodies, and certain mouse tissue cells could glow under ultraviolet light. By engineering the plasmid DNA this way, it was possible to see whether it was still functional upon its return to Earth.
After the rocket was recovered, DNA was collected from all the application sites. About 35 percent of the DNA was still able to mediate antibiotic resistance in bacteria and fluorescent marker expression in eukaryotic cells. Most of the DNA was found inside the grooves of the screw heads, which presented a 53 percent survival rate.
“It is conceivable that life exists independently from our planet even under the very hostile conditions prevailing on our neighbors like Mars,” wrote senior study author and molecular biologist Dr. Oliver Ullrich and his colleagues at the University of Zurich, according to The Los Angeles Times. “Already on Earth we are able to identify some extreme life forms which can survive physically and/or geochemically harsh conditions, such as very high or low temperatures, intense radiation, pressure, vacuum, desiccation, salinity, and pH. Many of these parameters also prevail in space and therefore the question is whether terrestrial organisms are able to survive a voyage through space.”
This discovery adds further credibility to the panspermia theory, or the prospect of life being able to survive outside Earth.
The panspermia theory, according to Northwestern University, suggests that life began between 4 and 3.8 billion years ago, when our planet endured a powerful, extensive series of meteor showers. Since life on Earth is believed to have exist 3.83 billion years ago, coinciding with this bombardment phase, these life forms should have faced extinction, but somehow endured.
For life to exist elsewhere in the universe, there must be an environment that can support this life. Life as we know it would have a hard time surviving outside Earth, but as the panspermia theory suggests, if life can withstand such extreme conditions, then it should be able to survive outside Earth.
“A critical question is if microorganisms do not only survive the residence in space,” said the researchers at the University of Zurich, “but would they also be able to withstand the hostile conditions of entering a planet’s atmosphere when they are situated, e.g. on a meteorite.”