London, June 26 (ANI): A new laboratory study has suggested that blasting the atmosphere of Saturn's moon Titan with X-rays can produce DNA building blocks, a finding that adds to evidence that Titan may be ripe for life.
According to a report in New Scientist, researchers led by Sergio Pilling of the Catholic University of Rio de Janeiro in Brazil have produced adenine, one of five base components of DNA and RNA, in Titan-like conditions.
Instead of using UV light, however, they used low-energy, or "soft", X-rays.
"Soft X-rays can penetrate deeper in Titan's atmosphere and reach denser regions (than UV)," Pilling told New Scientist, adding that X-rays set off different chemical reactions in Titan's atmosphere.
They modelled Titan's current atmosphere using a mixture of nitrogen and methane gas, and added water to it to simulate the conditions when the moon is bombarded with water-bearing comets or asteroids - a situation that occurred much more frequently in the early solar system.
A frozen sheet of salty water ice lay below this 'atmosphere' and caused the gas to condense into liquid droplets, like dew settling onto Titan's icy surface.
Then, the researchers bombarded the setup with X-rays for up to three days, representing the radiation that Titan would get from the sun over a period of about 7 million years.
Afterwards, the still-frozen surface contained some organic compounds, but nothing that could be called the building blocks of life.
But when they heated the samples to room temperature, adenine appeared.
That means Titan's saucepan of proto-life would need a source of extra heat to activate.
If there was a warm period in Titan's history, perhaps prompted by volcanic activity or meteoroid impacts, "a primitive life could have had a chance to flourish there," according to the researchers.
Titan is due to be heated up in the next few billion years, when the sun bloats into a red giant star, expanding to the present orbit of Earth, they added.
According to Chris McKay, an astrobiologist at NASA, if impacts sometimes allow water to exist on the moon's surface, then things might happen.
"It is interesting to see how far the chemistry can go," he said. (ANI)