For those who believe that life on Earth came from another planet or galaxy on an asteroid or a comet (panspermia), this is exciting news. Scientists attached DNA to the outside of a rocket and the strands survived the launch, trip into space and intense heat of re-entry intact
According to a recent report published in PLOS ONE, the purpose of the Texus-49 sub-orbital mission launched from Kiruna, Sweden, was to study the affect of gravity on the genes of human cells traveling inside the rocket. At the last minute, researchers from the University of Zurich painted small, double-stranded DNA molecules on the outside shell of the payload section of the rocket. On this sub-orbital flight, the exterior was exposed to temperatures exceeding 1,000°C (1,800°F).
Inspecting the rocket upon return, the scientists found that 53 per cent of the DNA remained in the grooves of screw heads and a third of it was fully functional. The DNA contained genes for fluorescence and antibiotic resistance and proved their functionality by transferring antibiotic resistance to bacteria and driving a fluorescent marker in cells.
Dr. Cora Thiel, one of researchers, said:
We were completely surprised to find so much intact and functionally active DNA.
What do these results mean? Professor Oliver Ullrich, who headed the test, explained:
This study provides experimental evidence that the DNA's genetic information is essentially capable of surviving the extreme conditions of space and the re-entry into Earth's dense atmosphere.
This also means that spaceships from Earth could contaminate other worlds with whatever might be attached to the outside, Ullrich warns.
The results show that it is by no means unlikely that, despite all the safety precautions, space ships could also carry terrestrial DNA to their landing site. We need to have this under control in the search for extraterrestrial life.