Washington, Jul 29 (IANS): NASA scientists have discovered a chemical in the atmosphere of Saturn's largest moon Titan that, even under the harsh conditions on the planet, is capable of forming stable, flexible structures similar to cell membranes.
On Earth, acrylonitrile, also known as vinyl cyanide, is useful for manufacturing plastics.
NASA researchers identified the chemical fingerprint of acrylonitrile in Titan data collected by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.
The team found large quantities of the chemical on Titan, most likely in the stratosphere -- the hazy part of the atmosphere that gives this moon its brownish-orange colour.
"We found convincing evidence that acrylonitrile is present in Titan's atmosphere, and we think a significant supply of this raw material reaches the surface," said Maureen Palmer, researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
The cells of Earth's plants and animals would not hold up well on Titan, where surface temperatures average minus -179 degrees Celsius and lakes brim with liquid methane.
Acrylonitrile molecules could come together as a sheet of material similar to a cell membrane.
"The ability to form a stable membrane to separate the internal environment from the external one is important because it provides a means to contain chemicals long enough to allow them to interact," said Michael Mumma, director of the Goddard Center for Astrobiology.
"If membrane-like structures could be formed by vinyl cyanide, it would be an important step on the pathway to life on Saturn's moon Titan," he added in a paper published in the journal Science Advances.
The Goddard team determined that acrylonitrile is plentiful in Titan's atmosphere, present at concentrations up to 2.8 parts per billion.
"The detection of this elusive, astrobiologically relevant chemical is exciting for scientists who are eager to determine if life could develop on icy worlds such as Titan," said Martin Cordiner, senior author.
"This finding also adds an important piece to our understanding of the chemical complexity of the solar system," he added.